REVERSIBILITY OF GASOLINE SULFUR EFFECTS … › downloads › api-report-sulfur...The impact of...

API Contract No. 2012-106409

REVERSIBILITY OF GASOLINE SULFUR EFFECTS ON EXHAUST EMISSIONS

FROM LATE MODEL VEHICLES

June 20, 2013

Prepared for:

American Petroleum Institute 1220 L Street, NW

Washington, DC 20005 www.api.org

Prepared by:

SGS Environmental Testing Corporation Keith Vertin and Aaron Reek

2022 Helena St. Aurora, CO 80011 (303) 344-5470

www.sgs.com/etc

http://www.api.org/

http://www.sgs.com/etc

This page intentionally blank

API 2012-106409 FUEL SULFUR REVERSIBILITY STUDY

i

REVERSIBILITY OF GASOLINE SULFUR EFFECTS ON EXHAUST EMISSIONS FROM LATE MODEL VEHICLES

Table of Contents

List of Figures ................................................................................................................................................. ii List of Tables ................................................................................................................................................. iii Abbreviations and Acronyms ....................................................................................................................... iv Acknowledgements ....................................................................................................................................... v 1.0 Executive Summary ........................................................................................................................... 1 2.0 Introduction ....................................................................................................................................... 2 3.0 Test Plan for the Fuel Sulfur Reversibility Study ............................................................................... 4 4.0 Fuel Specification and Preparation ................................................................................................... 6 5.0 Vehicle Model Selection and Description .......................................................................................... 8 6.0 Preparation for Testing .................................................................................................................... 12

6.1 Catalyst and Sensor Aging ........................................................................................................... 12 6.2 Chassis Dynamometer Lab and Emissions Measurement ........................................................... 16 6.3 Vehicle Preparation and As-Received Exhaust Emissions ........................................................... 20

7.0 Sulfur Reversibility Study – Individual Vehicle Test Results ............................................................ 22 7.1 API01 2009 Chevrolet Malibu ...................................................................................................... 23 7.2 API02 2012 Honda Civic EX .......................................................................................................... 25 7.3 API03 2012 Hyundai Sonata ........................................................................................................ 27 7.4 API04 2012 Ford Focus ................................................................................................................ 29 7.5 API05 2012 Audi A3 ..................................................................................................................... 31 7.6 API06 2012 Toyota Camry ........................................................................................................... 33 7.7 Comparison of Vehicle Exhaust Temperatures and Emissions ................................................... 35 7.8 Raw Emissions and Catalyst Efficiency Data ................................................................................ 39 7.9 Comparison of API01 Malibu NOx Results with the Umicore Study ........................................... 41 7.10 Reversibility Data Tables ............................................................................................................. 43

8.0 Sulfur Reversibility Study Results - Statistical Analysis.................................................................... 48 8.1 Statistical Analysis Approach ....................................................................................................... 48 8.2 Statistical Analysis Results and Discussion .................................................................................. 51

9.0 Summary and Conclusions .............................................................................................................. 56 10.0 References ....................................................................................................................................... 57 11.0 Appendices ...................................................................................................................................... 59

11.1 Fuel Sulfur Monitoring Results for Emissions Test Fuels ............................................................. 59 11.2 Certificate of Analysis for Emissions Test Fuels ........................................................................... 60 11.3 Catalyst Aging Test Fuel Properties ............................................................................................. 76 11.4 Exhaust and Catalyst Temperature Histograms for Aging Test ................................................... 77 11.5 Dynamometer Equivalent Test Weights and Road Load Coefficients ......................................... 83 11.6 Manufacturer Recommended Motor Oils ................................................................................... 83 11.7 Catalyst Warm-Up and NOx Light-Off for Each Vehicle, Reversibility Sequence, FTP75 ............ 84 11.8 Raw Exhaust Emissions and Catalyst Conversion Efficiency........................................................ 90 11.9 Soot, Particle Number and Size Distribution Reports ................................................................. 98


ii

List of Figures Figure 1. Vehicles Selected for the Gasoline Sulfur Effects Study ................................................................9 Figure 2. Catalyst Aging on JMT Engine Stand: V-8 Engine (Top), Multi-leg Exhaust System (Bottom) .... 12 Figure 3. Typical Exhaust System Instrumentation for Catalyst Aging Test .............................................. 14 Figure 4. Air-Fuel Ratio Histogram for Vehicle API01 over the 225 hour Aging Run................................. 14 Figure 5. Exhaust Inlet, Close Coupled Catalyst and Underbody Catalyst Temperature Histograms for Vehicle API01 over the 225 hour Aging Run............................................................................................... 15 Figure 6. API02 Civic in SGS-ETC Site 2 Chassis Dynamometer Emissions Lab .......................................... 16 Figure 7. Emissions Sampling Arrangement .............................................................................................. 17 Figure 8. Catalyst Bed Temperatures for 2009 Malibu at 5440 feet and 960 feet Elevation – FTP75 ...... 19 Figure 9. Catalyst Bed Temperatures for 2009 Malibu at 5440 feet and 960 feet Elevation – US06 ....... 20 Figure 10. Typical Exhaust System Instrumentation for Vehicle Emissions Tests ..................................... 21 Figure 11. Sulfur Reversibility Test Results, API01 Malibu ........................................................................ 24 Figure 12. Sulfur Reversibility Test Results, API02 Civic ............................................................................ 26 Figure 13. Sulfur Reversibility Test Results, API03 Sonata ........................................................................ 28 Figure 14. Sulfur Reversibility Test Results, API04 Focus .......................................................................... 30 Figure 15. Sulfur Reversibility Test Results, API05 A3 ............................................................................... 32 Figure 16. Sulfur Reversibility Test Results, API06 Camry ......................................................................... 34 Figure 17. Segment of the EPEFE Cycle Used for Catalyst Sulfur Purge .................................................... 35 Figure 18. Catalyst Warm-Up and NOx Light Off Comparison, 10ppm Sulfur Fuel ................................... 37 Figure 19. Soot Emissions Comparison in CVS Diluted Exhaust Stream, 10 and 80 ppm Sulfur Fuels ...... 38 Figure 20. Conversion of Hydrocarbons Across Close Coupled and Underbody Catalysts, Vehicle API05 39 Figure 21. NOx Conversion Across Close Coupled and Underbody Catalysts, Vehicle API03 .................... 40 Figure 22. 2009 Malibu NOx Emissions – Comparison between Umicore and API Fuel Sulfur Studies ..... 42 Figure 23. Sensitivity of API01 Underbody Catalyst NOx Conversion to Fuel Sulfur .................................. 43 Figure 24. Data Distributions for NOx and Soot Emissions ........................................................................ 49 Figure 25. Difference in Mean Emissions and 95% Confidence Intervals for 10 ppm Sulfur Fuel ............. 52 Figure 26. Soot and PN Correlation for Vehicle API04, 10 ppm and 80 ppm Fuels.................................... 53 Figure 27. Difference in Mean Emissions and 95% Confidence Intervals for 10 ppm Sulfur Fuel ............. 54


iii

List of Tables

Table 1. Test Sequence for Each Vehicle in the Sulfur Sensitivity Study ......................................................4 Table 2. Base Fuel Properties and Comparison with California LEV III Certification Fuel Standard .............7 Table 3. Test Fuel Names and Descriptions ..................................................................................................7 Table 4. Vehicle Models and Emissions Certification Label Information .....................................................9 Table 5. Vehicle ID Number, Emissions Control Equipment and Catalyst Summary................................. 10 Table 6. Catalyst Arrangement for Engine Stand Aging Runs .................................................................... 13 Table 7. Median and Peak Catalyst Exposure Temperatures over Aging Period (225 hours) ................... 16 Table 8. As-Received Vehicle Exhaust Emissions, FTP75, Federal Certification Gasoline ......................... 21 Table 9. Typical Exhaust Gas and Catalyst Bed Temperatures for EPEFE Cycle WOT Events .................... 35 Table 10. Median and Peak Catalyst Temperatures for the US06 and FTP75 Cycles, 10ppm Sulfur Fuel . 36 Table 11. Coefficient of Variation for Raw Exhaust Emissions, FTP75, 10 ppm Sulfur Fuel ....................... 41 Table 12. 2009 Malibu SULEV-II PZEV Fuel Sulfur Studies – Catalyst Aging and Test Fuels ....................... 42 Table 13. Fuel Sulfur Reversibility Study Dataset for Analysis, API01 and API02 ...................................... 44 Table 14. Fuel Sulfur Reversibility Study Dataset for Analysis, API03 ........................................................ 45 Table 15. Fuel Sulfur Reversibility Study Dataset for Analysis, API04 ........................................................ 46 Table 16. Fuel Sulfur Reversibility Study Dataset for Analysis, API05 and API06 ...................................... 47 Table 17. Mean Emissions and 95% Confidence Intervals from Statistical Analysis .................................. 55


iv

Abbreviations and Acronyms

API American Petroleum Institute CALEV3_10 California LEV III regular octane gasoline, nominal 10ppm sulfur content CALEV3_xx California LEV III regular octane gasoline fuel doped to a sulfur content of xx ppm CC, CCC Close Coupled or Close Coupled Catalyst CFR Code of Federal Regulations CH4 Methane CO Carbon monoxide CO2 Carbon dioxide COV Coefficient of Variation CPC Condensation Particle Counter CVS Constant Volume Sampling EEPS Engine Exhaust Particle Sizer EPA U.S. Environmental Protection Agency EPEFE Reference to the sulfur purge drive cycle developed by the European Programme on

Emissions, Fuels and Engine Technologies FID Flame Ionization Detector FTP75 Federal Test Procedure consisting of a 3-phase drive cycle GDI Gasoline Direct Injection HC Total hydrocarbons I/M Inspection/Maintenance readiness state in on-board diagnostic system JMT Johnson Matthey Vehicle Testing and Development, Taylor, Michigan LA4 2-phase drive cycle also known as the FTP72 or Urban Dynamometer Driving Schedule mg Milligrams MILs/DTCs Manufacturer Indicator Lamp or Diagnostic Trouble Codes NEDC New European Driving Cycle NMOG Non Methane Organic Gases, estimated as NMHC*1.1012 for E10 gasoline NOx Oxides of nitrogen ppm Parts per million PM Particulate Matter, measured gravimetrically in this study PN Particle Number, for accumulation mode particles measured per Euro 6 PMP protocol PRLEV3_10 California LEV III premium octane gasoline, nominal 10ppm sulfur content PRLEV3_xx California LEV III premium octane gasoline fuel doped to a sulfur content of xx ppm PSD Particle Size Distribution PZEV Partial Zero Emissions Vehicle category within California LEV II Standards RVP Reid Vapor Pressure SFI Sequential multi-port fuel injection system SGS-ETC SGS Environmental Testing Corporation, Aurora, Colorado SGS-OGC SGS Oil, Gas and Chemical Analytical Laboratory, Deer Park, Texas SRC EPA Standard Road Cycle SULEV-II Super Ultra Low Emissions Vehicle category within California LEVII Standards TC K-type thermocouple UB, UBC Underbody or Underbody Catalyst US06 US06 Supplemental Federal Test Procedure, a high speed and acceleration drive cycle WOT Wide Open Throttle


v

Acknowledgements

The authors wish to thank the following individuals for their significant contributions to this study: Myles Weddington, Brad Kotch, Dave Reeves, David Meyer, Jeff Reed, David Casias, Joe Schmidt, Brad Farmer and Krystal Lewis at SGS Environmental Testing Corporation in Aurora Colorado; and Thomas Villeneuve and Dominic Margitan for their catalyst aging expertise at Johnson Matthey Testing in Taylor Michigan. Special thanks go to Gary Fenton of Air Academy Associates for review and discussion of the statistical analysis approach.

The authors also acknowledge the technical contributions and support from participating API members:

David Lax American Petroleum Institute King Eng Shell James Uihlein Chevron James Williams American Petroleum Institute Garry Gunter Phillips 66 Mani Natarajan Marathon Petroleum Matt Watkins ExxonMobil Phil Heirigs Chevron Fred Cornforth Phillips 66 Jim Simnick BP


Page 1

1.0 Executive Summary

On March 29, 2013 the US Environmental Protection Agency (EPA) released a proposed rule for Tier 3 Motor Vehicle Emission and Fuel Standards. The proposed NMOG+NOx tailpipe standards for light-duty vehicles represent approximately an 80% reduction from today’s fleet average. EPA is also proposing that federal gasoline contain no more than 10 ppm of sulfur on an annual average basis by 2017. There are several proposals with regards to the fuel sulfur cap, including either to maintain the current 80 ppm refinery gate and 95ppm downstream caps or to lower them to 50 and 65 ppm, respectively. Currently, federal regulations limit the sulfur content of gasoline to a 30 ppm annual average and a maximum cap of 80 ppm.

Sulfur is known to poison precious metal based three-way catalyst exhaust emission control systems. The impact of gasoline sulfur on older vehicle technologies ranging from Tier 0 to ULEV is relatively well understood. In contrast, there is a lack of test data on the sensitivity and reversibility of very low emitting vehicles (e.g., SULEV-II, PZEV, and Tier 2 Bin 2) to gasoline sulfur, especially for vehicles aged to full useful life. Further research is needed to evaluate late model vehicle emissions using the low levels of fuel sulfur proposed in the EPA Tier 3 rule.

This present study has tested six late model vehicles to determine if the exhaust emissions effects caused by exposure to 80 ppm sulfur fuel were reversible, after the vehicle was refueled with 10 ppm sulfur fuel. The reversibility test sequence included three segments: four baseline emissions tests run on 10 ppm sulfur fuel, three high sulfur fuel exposure tests using 80 ppm fuel, and three tests run after the vehicle was switched back to 10 ppm fuel. Each vehicle was driven 125 miles during the initial baseline tests using 10 ppm sulfur gasoline, followed by approximately 372 miles of operation on the 80 ppm sulfur gasoline, and 72 miles after refueling with 10 ppm sulfur fuel. The base fuel was a California LEVIII certification gasoline containing 10%vol ethanol. The 80 ppm fuel was produced by doping the base fuel with a representative mixture of sulfur compounds.

Test vehicles included a 2009 Chevrolet Malibu, 2012 Honda Civic, 2012 Hyundai Sonata, 2012 Ford Focus, 2012 Audi A3, and 2012 Toyota Camry. All vehicles were certified to California SULEV-II / PZEV emissions standards except the Camry, which was Federal Tier 2 Bin 5. The vehicles represented a wide range of emission control technologies. The Sonata, Focus and A3 were equipped with wall-guided gasoline direct injection engines. The vehicles were selected to represent the latest in powertrain and emissions controls technology, and were tested as a surrogate for EPA Tier 3 vehicles which are not yet commercially available.

New catalytic convertors and sensors were procured and aged on an engine stand to the equivalent of 120,000 to 150,000 miles. The aged catalysts and sensors were then installed on six vehicles for emissions testing.

FTP75 emissions tests were performed. Raw gaseous emissions were measured to quantify catalyst efficiency, and bag dilute emissions were collected to determine accurate mass emissions for analysis. Particulate matter, soot mass, particle number, and particle size distribution measurements were also made.


Page 2

The vehicles responded quite differently to changing sulfur content. Emissions trends, catalyst temperature data, catalyst warm-up information and particulate comparisons are made in the report. Five of the six vehicles tested using 10 ppm sulfur fuel had emissions under the proposed EPA Tier 3 Bin 30 FTP75 standard of 0.03 g/mile for NMOG+NOx.

This study aimed to provide independent and objective test results to the API for use in the EPA Tier 3 rule making process. The following conclusions were reached:

Gaseous exhaust emissions were higher for the vehicles conditioned and tested using 80 ppm sulfur fuel, relative to baseline tests run using 10 ppm fuel. Mean emissions increased for vehicles run on the 80 ppm fuel as follows, with greater than 95% confidence:

o Fleet average NMOG increased by 20% (0.002 g/mile change) o Fleet average NOx increased by 58% (0.006 g/mile change) o Fleet average CO increased by 31% (0.078 g/mile change) o Vehicle API02 (Civic) CO emissions increased by 54% (0.083 g/mile change) o Vehicle API03 (Sonata) NOx emissions increased by 74% (0.004 g/mile change), noting

that mean emissions of 0.009 g/mile remained well under the SULEV-II standard

For the fleet of six vehicles, average soot and PN emissions were not statistically different for 80 ppm fuel compared to 10 ppm fuel results. Only vehicle API03 (Sonata), the highest PM emitter in the study, had higher soot and PN emissions using 80 ppm fuel:

o Vehicle API03 (Sonata) soot emissions increased by 11% (0.41 mg/mile change) o Vehicle API03 (Sonata) PN emissions increased by 17% (9.6x1011 #/mile change)

For each vehicle tested on 10 ppm sulfur fuel, the NMOG, NOx, CO, Soot and PN emissions were found to be reversible following exposure to 80 ppm sulfur fuel. There was greater than 95% confidence that the differences in the mean emissions values measured before and after the high sulfur fuel exposure were not statistically different.

For the fleet of six vehicles combined, the NMOG, NOx, CO, Soot and PN emissions were found to be reversible following exposure to 80 ppm sulfur fuel.

Vehicles equipped with GDI engines had about five to seven times higher soot mass and particle number emissions on average compared to the SFI-equipped vehicles.

Vehicles equipped with GDI engines had very high variability in soot and PN emissions. The vehicle emissions variability was shown to be far larger than the fuel sulfur effect under study.

2.0 Introduction

On March 29, 2013 the US Environmental Protection Agency (EPA) released a proposed rule for Tier 3 Motor Vehicle Emission and Fuel Standards [Ref. 1]. The proposed NMOG+NOx tailpipe standards for light-duty vehicles represent approximately an 80% reduction from today’s fleet average. A 70% reduction in particulate matter (PM) standards is also proposed. Many of the proposed Tier 3 standards are harmonized with California LEV III standards.


Page 3

EPA is also proposing that federal gasoline contain no more than 10 ppm of sulfur on an annual average basis by 2017. There are several proposals with regards to the fuel sulfur cap, including either to maintain the current 80 ppm refinery gate and 95 ppm downstream caps or to lower them to 50 and 65 ppm, respectively. Currently, federal regulations limit the sulfur content of gasoline to a 30 ppm annual average and a maximum cap of 80 ppm.

Sulfur is known to poison precious metal based three-way catalyst exhaust emission control systems. A number of studies were conducted by industry and government agencies in the US, Europe and Japan in the late 1980s and during the 1990s to evaluate the sensitivity of gasoline vehicle exhaust emissions to changes in fuel sulfur content as well as the reversibility of the sulfur poisoning effect. In 1991 the Auto/Oil Air Quality Improvement Research Program demonstrated the sulfur poisoning effect was reversible [Ref. 2]. That is, following exposure to high sulfur gasoline the catalyst performance recovered when switching back to lower sulfur gasoline. In the European EPEFE program [Ref. 3], researchers tested fuels containing 18 and 382 ppm sulfur, and reported that benefits of lower sulfur fuel were strongly dependent on the precious metal formulation used for the catalyst coatings. The Coordinating Research Council evaluated the effect of driving cycle on catalyst reversibility using fuels with 30 and 630 ppm sulfur [Ref. 4]. The study included a comprehensive statistical analysis that concluded the poisoning effect was completely or partially reversible. Consequently, the impact of gasoline sulfur on vehicle technologies ranging from Tier 0 to ULEV is relatively well understood. In contrast, there is a lack of test data on the sensitivity of very low emitting vehicles (e.g., SULEV-II, PZEV, and Tier 2-Bin 2) to gasoline sulfur, and the reversibility of those effects. One study, conducted by Umicore Autocat USA [Ref. 5], measured the impact of test fuels containing 3 ppm and 33 ppm sulfur on NOx emissions from only one vehicle - a 2009 model year PZEV Malibu. Results were only reported for the underbody catalyst. In addition to measuring sulfur sensitivity, the authors also found that use of a high exhaust flow/high engine load driving cycle such as the US06 reversed the sulfur poisoning associated with operation on 33 ppm sulfur fuel.

Previous research has shown that both sulfur sensitivity and sulfur reversibility are influenced by a number of vehicle operating characteristics (e.g., air/fuel ratio control, catalyst temperatures) and emission control system design, configuration and catalyst formulation. In contrast, the emissions of late model vehicles to low sulfur levels is not well understood for very low sulfur fuels, and especially for vehicles aged to full useful life. Further research is needed to evaluate late model vehicle emissions using the low levels of fuel sulfur proposed in the EPA Tier 3 rule.

This present study has tested six late model vehicles to determine if the exhaust emissions effects caused by exposure to 80 ppm sulfur fuel were reversible, after the vehicle was refueled with 10 ppm sulfur fuel. The reversibility test sequence included four baseline tests run on 10 ppm sulfur fuel, three high sulfur fuel exposure tests using 80 ppm fuel, and three tests after the vehicle was switched back to 10 ppm fuel. The base fuel was a California LEVIII certification gasoline containing 10%vol ethanol. The 80 ppm fuel was produced by doping the base fuel with a mixture of sulfur compounds.

New catalytic convertors and sensors were procured and aged on an engine stand to the equivalent of 120,000 to 150,000 miles, using an aging fuel with a sulfur range of 18.5 to 43 ppm. The aged catalysts and sensors were then installed on six vehicles for emissions testing. FTP75 emissions tests were performed. The results from this sulfur reversibility study are discussed in this report.


Page 4

3.0 Test Plan for the Fuel Sulfur Reversibility Study

The reversibility of fuel sulfur effects on vehicle exhaust emissions was studied using a protocol similar to previous research [Ref. 4, 5]. The dynamometer test sequence was designed to allow comparison of results with the 2009 Malibu PZEV tested using “Test Combination Two” from [Ref. 5].

New catalytic convertors and sensors were procured and aged on an engine stand to the equivalent of 120,000 to 150,000 miles (Section 6.1). The aged catalysts and sensors were then installed on the late model vehicles for testing. Each vehicle was then tested using a base fuel with 10 ppm sulfur concentration, exposed to 80ppm fuel and tested, and then retested on 10ppm fuel. The fuels and vehicles are described in Sections 4 and 5, respectively. The objective of the experiment was to determine if the vehicle exhaust emissions from tests run using 10 ppm sulfur gasoline were statistically different following the exposure to 80 ppm sulfur fuel. The test sequence run for each vehicle is shown in Table 1.

Table 1. Test Sequence for Each Vehicle in the Sulfur Sensitivity Study

Description Procedure Miles

Cumulative

Miles for

Segment

Catalyst Sulfur Purge, 10ppm Sulfur Fuel Double Drain and 70% Refill

EPEFE + 2 LA4 Sulfur Purge and Conditioning Cycles 42.2

Baseline Emissions, 10ppm Sulfur Fuel 12 to 24 Hour Soak

FTP75 Emissions Test 11.1

2 LA4 + 1 US06 Preparation Cycle 22.9

12 to 24 Hour Soak


1 US06 Preparation Cycle 8.0

12 to 24 Hour Soak



12 to 24 Hour Soak

FTP75 Emissions Test 11.1 125.4

Exposure to 80ppm Sulfur Fuel Double Drain and 100% Refill

300 Miles on Dynamometer, Standard Road Cycle 300.0

70% Refill


12 to 24 Hour Soak



12 to 24 Hour Soak



12 to 24 Hour Soak


Establish Degree of Reversibility, 10ppm Sulfur Fuel Double Drain and 70% Refill


12 to 24 Hour Soak



12 to 24 Hour Soak



12 to 24 Hour Soak



Page 5

The test sequence began with an EPEFE cycle consisting of ten WOT events to elevate exhaust and catalyst temperatures for sulfur purge. Previous studies have shown the EPEFE cycle is an effective means for catalyst sulfur purge. The EPEFE + 2 LA4 cycles served to condition all vehicles uniformly using 10 ppm low sulfur, prior to the baseline emissions tests.

The purpose of the four baseline tests was to establish vehicle exhaust emissions using the 10 ppm low sulfur fuel, following the catalyst sulfur purge and prior to the 80 ppm sulfur fuel exposure. The baseline emissions were the basis for comparison, used to quantify fuel sulfur sensitivity and reversibility effects for the tests that followed.

A US06 prep cycle was performed in lieu of an LA4 prep cycle, prior to each soak period and FTP75 emissions test. The LA4 and FTP75 cycles used for emissions certification purposes reach a top vehicle speed of only 56.7 mph, and exhaust temperatures are low in comparison to other chassis dynamometer cycles. Therefore, repeated dynamometer testing using the LA4 and FTP75 cycles was not necessarily representative of real-world driving. The US06 cycle was developed to address the shortcomings with the FTP75 test cycle, to better represent higher speed and higher acceleration driving behavior. Data from the US Federal Highway Administration show that nearly 46% of the average daily vehicle miles of travel at posted speeds of 60 mph or higher occurs on urban roads [Ref. 6]. To better represent real-world driving behavior, the reversibility test sequence used in this study included alternating US06 and FTP75 cycles, to encompass both higher speed and lower speed vehicle operation.

Following the change to 80ppm fuel, each vehicle was conditioned on the chassis dynamometer for 300 miles using the EPA Standard Road Cycle. Three emissions tests were then run to determine the sensitivity of vehicle exhaust emissions to catalyst poisoning that occurred during exposure to the 80 ppm sulfur fuel.

The vehicle fuel tank was then drained and refilled with 10 ppm sulfur fuel and triplicate emissions tests were run. These final tests were performed to determine if the exhaust emissions effects caused by 80ppm sulfur fuel exposure were reversible. That is, the exhaust emissions were compared with the baseline emissions, to determine if there were any statistical differences in results before and after the 80ppm fuel exposure.

Special care was taken to ensure fuel purges were complete and the vehicle was conditioned on each fuel before emissions testing began. The start of the sequence included a double drain and fuel fill, followed by an EPEFE sulfur purge cycle and two LA4 cycles. The EPEFE cycle consisted of a series of ten WOT accelerations that significantly elevated the exhaust temperatures to promote sulfur purge from the catalyst [Ref. 7]. The subsequent LA4 cycles served as a prep cycle for conditioning the vehicle prior to emissions testing. Fuel drains were performed at the fuel rail to ensure a complete drain.

The test fuel and sulfur content were carefully controlled for the experiment. Fuel sulfur concentration was held within a ±2ppm tolerance for all test fuels (Section 4). Some other inputs that effected emissions responses are included below, with control measures noted in parentheses:

Vehicle model

Engine out emissions (consistent fuel conditioning and prep cycle used)

Catalyst conversion efficiency (consistent fuel conditioning and prep cycle used)

Driver (same driver used for nearly all tests, no driver violations accepted)

Lab-to-lab variability (same chassis dyno emission lab used for all tests)


Page 6

Day-to-day lab variation, drift (calibration procedures and data quality control)

The primary responses of interest for the reversibility analysis included FTP75 weighted NMOG, NOx, CO, MPG, soot mass, and Particle Number (PN). All gaseous emissions were measured from CVS sample bags, and particulate measured from a full dilution tunnel. NMOG emissions were estimated from NMHC measurements, per Section 6.2. Many other measurements were made for each phase of the FTP75 emissions test, and are cited in the results section and Appendix of the report.

4.0 Fuel Specification and Preparation

The base fuel for the study was California LEV III certification gasoline [Ref. 8]. This specification has 8 to 11 ppm sulfur, and nominal ethanol content of 10%vol. The certification fuel has a regular and premium octane specification. The antiknock index, (R+M)/2, is 87 to 88.4 for regular unleaded and 91 minimum for premium unleaded.

Five of the six vehicles in the study were approved by the manufacturers for operation on regular octane fuels (Section 5). One vehicle had a turbocharged engine and was selected to increase the diversity of powertrain technology to be tested. The turbocharged engine required premium octane fuel. Therefore, regular and premium octane base fuels were procured for the study.

At the start of the project, the California LEVIII certification fuel was not commercially available. The base fuels were therefore made-to-order fuel batches formulated specifically for this project. The base fuels were ordered with 10 ppm sulfur content and a TOP TIER detergent additive. The base fuel properties are compared with the California LEVIII specification in Table 2. Fuel property results are provided for regular and premium octane base fuels. Data from the certificate of analysis (Haltermann) and from an independent laboratory (SGS-OGC) are presented. Most fuel property results were within the specification, but a few properties were at or just over limit.

A mixture of sulfur compounds was added to the base fuels to prepare the test fuels with 80 ppm sulfur concentration. The sulfur mixture consisted of 4 wt% dimethyldisulfide, 23 wt% thiophene, and 73 wt% benzothiophene, representing the types and distribution of sulfur compounds present naturally in gasoline [Ref. 9]. Four test fuels were prepared for the project, with identifying names per Table 3.

The test fuels were dispensed into drums. Because fuel sulfur was a critical control parameter in the study, the fuel sulfur content in the drummed fuel was monitored. Samples were drawn from multiple drums and sent for analysis (Appendix 11.1). The test fuels all had sulfur concentration within ±2ppm of the nominal value, and well within the ±3ppm tolerance set for the study.

The certificate of analysis for each fuel is provided in Appendix 11.2.


Page 7

Table 2. Base Fuel Properties and Comparison with California LEV III Certification Fuel Standard

Table 3. Test Fuel Names and Descriptions

Fuel Name ---> ASTM CALEV3_10 CALEV3_10 PRLEV3_10 PRLEV3_10 CA LEVIII

Laboratory ---> Method Units Haltermann SGS-OGC Haltermann SGS-OGC Specification

Distillation D86

IBP F 107 109.9 109 108.9

10% F 137 138.6 136 138.2 130-150

50% F 214 212.4 212 208 205-215

90% F 316 314.2 316 314.1 310-320

EP F 352 345.9 357 349.5 390 max

Sulfur D5453 ppm 9 9 9 9 8-11

RVP D5191 psi 7.2 7.35 7.2 7.25 6.9-7.2

Ethanol D4815 %vol 9.8 9.64 10.2 10.08 9.8-10.2

Lead D3237 g/gal None <0.01 None <0.01 0.1 max

Unwashed Gum Content D381 mg/100ml 8.4 16.5 19.5 15.5

Solvent Washed Gum Content D381 mg/100ml <0.5 <0.5 <0.5 <0.5 3 max

Copper Strip Corrosion D130 Rating 1a 1a 1a 1a 1

Silver Strip Corrosion

D4814

Annex A1 Rating NA 0 NA 0

Oxidation Stability D525 min 1000+ >240 1000+ >240 1000 min

Density @ 60F D4052 g/cm3 0.7496 0.7493 0.7465 0.7464

Carbon D5291 %mass 82.88 82.2 82.39 81.9

Hydrogen D5291 %mass 13.65 13.4 13.82 13.6

Oxygen D4815 %mass 3.6 3.52 3.76 3.7 3.3-3.7

Aromatics D1319 %vol 20.9 22.7 21.9 21.1 19.5-22.5

Saturates D1319 %vol 61.5 62.4

Olefins D1319 %vol 4.9 6.2 4.4 6.5 4-6

Multi-substituted Alkyl Aromatic HC D5769 %vol 14 NA 13 NA 13-15

RON D2699 Rating 92.3 92.4 97.8 98.2

MON D2700 Rating 83.4 84 88 87.8

Antiknock Index (R+M)/2

D2699

/D2700 Rating 87.85 88.2 92.9 93

87-88.4 (reg),

91 min (prem)

Sensitivity

D2699

/D2700 Rating 8.9 NA 9.8 NA 7.5 min

Auto Vapor/Liquid Ratio D5188 Rating NA 137 NA 137

Net Heating Value D240 BTU/lb 18027 NA 18118 NA

Phosphorous D3231 g/gal None NA None NA 0.005 max

Benzene D5580 %vol 0.6 NA 0.7 NA 0.6-0.8

MTBE D4815 %vol None NA None NA 0.05 max

REGULAR OCTANE PREMIUM OCTANE

Fuel Name Description

CALEV3_10 Regular Octane Base Fuel, California LEV III Specification, 10ppm Sulfur

CALEV3_80 Regular Octane Base Fuel doped to 80ppm Sulfur

PRLEV3_10 Premium Octane Base Fuel, California LEV III Specification, 10ppm Sulfur

PRLEV3_80 Premium Octane Base Fuel doped to 80ppm Sulfur


Page 8

5.0 Vehicle Model Selection and Description

This study differs from previous programs in that the focus is to test the latest technology vehicles on very low sulfur gasoline. API specified the six vehicle models for testing were to have the following emissions certifications:

One SULEV-II / PZEV vehicle, specifically the 2009 Chevrolet Malibu equipped with a 2.4L engine to allow comparison with testing performed at Umicore Autocat [Ref. 5]

Four vehicles certified to meet either the Federal Tier 2, Bin 2 exhaust emission standards or the California SULEV-II / PZEV exhaust emissions standards

One vehicle to represent a typical in-use Federal Tier 2 Bin 5 model

The vehicles were selected to represent the latest in powertrain and emissions controls technology, and were tested as a surrogate for EPA Tier 3 vehicles which are not yet commercially available. The preference was to select late model vehicles to represent a range of exhaust emission control system design configurations available on high selling models. The vehicles were to have accumulated between 5,000 to 10,000 miles of customer driving before testing. An exception was made for the 2009 Malibu, where a mileage between 10,000 and 20,000 miles was sought because all candidate vehicles were approximately three years of age at the time of recruitment.

Candidate vehicles were identified by searching for models meeting these emissions standards using the US EPA 2012 emissions database [Ref. 10]. From this search, all candidate vehicles certified to the SULEV-II / PZEV emissions standard were equipped with four cylinder engines.

In 2010, EPA and NHTSA introduced a final rule to jointly regulate greenhouse gas emissions and corporate average fuel economy. In response to increasing fuel economy requirements, there have been many new vehicle models introduced with gasoline direct injection (GDI) engines in the United States. Because movement to more fuel efficient GDI engine technology is expected to continue in the US, it was important to represent GDI technology in the study.

The vehicle models selected for the study are listed in Table 4 and shown in Figure 1. Five of the six vehicle models were certified to the California SULEV-II / PZEV emissions standards. Several of the vehicle models had the engine and evaporative family certified to both California and Federal emissions standards (Table 4). PZEV certification was verified from the vehicle emissions label. Three vehicle models were equipped with sequential multiport fuel injection (SFI) engines, and three with GDI engines. All vehicles in the study had stoichiometric combustion following warm-up, and employed three way catalyst technology.

All vehicles except the Audi A3 were approved for operation on regular unleaded gasoline. For the turbocharged Audi A3, the manufacturer recommended premium unleaded fuel. The Audi A3 was selected because there was high interest to include a turbocharged GDI in the study to expand the diversity of powertrain technology to be tested. Turbocharging and the effect of higher exhaust flow rates on catalyst performance were of interest. The inclusion of this model also meant that premium test fuels needed to be included in the study.

The Toyota Camry was chosen to represent Tier 2 Bin 5 vehicle technology, in part because it was available with a V6 engine and added further diversity to the powertrain technology to be tested. The


Page 9

Honda Civic EX was one of only two non-hybrid vehicle models certified to federal Tier 2 Bin 2 in 2012, according to the EPA database available at that time.

Table 4. Vehicle Models and Emissions Certification Label Information

Figure 1. Vehicles Selected for the Gasoline Sulfur Effects Study

The following inspections and checks were made for each vehicle before committing to its procurement:

Odometer between 5,000 and 10,000 miles (2009 Malibu between 10,000 and 20,000 miles)

Confirm vehicle never in accident and clean CarFax history

Confirm no active or pending MILs/DTCs

Vehicle in I/M readiness state

Inspect tires, belts and hoses

Inspect for any obvious vehicle modifications or tampering

Inspect exhaust system and perform leak check

Control

Number

Model

YearMake Model

Engine

Family Code

Evaporative

Emissions

Family Code

Engine

Automatic

Transmission

No. Gears

Emissions

Certification Standard

API01 2009 Chevrolet Malibu 9GMXV02.4026 9GMXR01237022.4L

SFI6

California LEV-II SULEV

and Federal Tier 2 Bin 5

API02 2012 Honda Civic EX CHNXV01.8VC2 CHNXR0111VZA1.8L

SFI5



API03 2012 Hyundai Sonata CHYXV02.4YPC CHYXR0155PPX2.4L

GDI6 California LEV-II SULEV

API04 2012 Ford Focus CFMXV02.0VZ2 CFMXR0110GBX2.0L

GDI6



API05 2012 Audi A3 CADXV02.03PA CADXR01102372.0L Turbo

GDI6



API06 2012 Toyota Camry CTYXV03.5BEC CTYXR0115A123.5L V6

SFI6 Federal Tier 2 Bin 5


Page 10

Inspect evaporative emissions system, perform pressure decay check

Perform road load derivation, and a preliminary cold start FTP75 emissions cycle using the vehicle’s street fuel to assess emissions

The five vehicles meeting SULEV-II standards were recruited from California and transported to SGS-ETC by car carrier for testing. The vehicle ID numbers, starting mileage, emissions control technology from the certification label, and catalyst arrangement are shown in Table 5. All vehicles except the Honda Civic EX employed a close coupled catalyst and underbody catalyst combination.

Table 5. Vehicle ID Number, Emissions Control Equipment and Catalyst Summary

The powertrain and emissions control technology is summarized below for each vehicle. Emissions control equipment was determined from the vehicle emissions labels, from CARB Executive Orders for emissions certifications, and from information published by the manufacturer. The number of substrates, substrate size, cell geometry and material could only be determined by cutting the catalyst cans open and was not completed at the time of this report.

API01 2009 Chevrolet Malibu

2.4L “LE5” I-4 engine Power: 169hp@6400rpm, Torque: 160lb-ft@4500rpm Sequential Multi-Port Fuel Injection Compression ratio = 10.4:1 16 valve, DOHC variable valve timing

Air injection/rich operation for fast catalyst light-off [Ref. 5]

Heated oxygen sensor

Three way catalysts: one close coupled catalyst, one underbody catalyst

API02 2012 Honda Civic EX

1.8L “i-VTEC” I-4 engine Power: 140hp@6500rpm, Torque: 128lb-ft@4300rpm Sequential Multi-Port Fuel Injection Compression ratio = 10.6:1 16 valve, SOHC variable valve timing

Exhaust Gas Recirculation

Heated air-fuel ratio sensor

Control

Number

Model

Year

Make and

ModelVehicle ID No. (VIN)

Odometer

(miles)Engine Equipment on Emissions Label Catalyst Arrangement

API01 2009Chevrolet

Malibu1G1ZH57B79F186689 10981 2.4L I4 SFI, HO2S, TWC, AIR One close coupled, one underbody

API02 2012Honda

Civic EX2HGFB2F90CH529133 5823 1.8L I4 TWC, AF SENSOR, HO2S, EGR, SFI One close coupled

API03 2012Hyundai

Sonata5NPEB4AC3CH365795 6845 2.4L I4 DFI, HO2S(2), WU-TWC, TWC One close coupled, one underbody

API04 2012Ford

Focus1FAHP3F28CL155154 5000 2.0L I4 TWC, H2OS, DGI, HAFS One close coupled, one underbody

API05 2012Audi

A3WAUKFAFM8CA000802 9028

2.0L I4

TurboDFI,TWC(2),HO2S(3),Air, CAC, TC, DOR One close coupled, one underbody

API06 2012Toyota

Camry4T1BK1FK5CU514551 5057 3.5L V6 SFI, 2A/FS, 2WU-TWC, 2HO2S, TWC Two close coupled, one underbody


Page 11


Three way catalyst: one close coupled catalyst

API03 2012 Hyundai Sonata

2.4L “Theta” I-4 engine Power: 200hp@6300rpm, Torque: 186lb-ft@4250rpm Gasoline Direct Injection, wall guided type Compression ratio = 11.3:1 16 valve, DOHC variable valve timing

Late injection for fast catalyst light off

Two heated oxygen sensors


API04 2012 Ford Focus

2.0L “Ti-VCT” I-4 engine Power: 160hp@6500rpm, Torque: 146lb-ft@4450rpm Gasoline Direct Injection, wall guided type Compression ratio = 12.0:1 16 valve, DOHC variable valve timing

Peak injection pressure of 2150 psi

Heated air-fuel ratio sensor



API05 2012 Audi A3

2.0L “FSI” I-4 engine Power: 200hp@5100rpm, Torque: 207lb-ft@1800-5000rpm Gasoline Direct Injection, wall guided type Turbocharged and intercooled Compression ratio = 9.6:1 16 valve, DOHC variable valve timing

Stratified lean operation on start and air injection for NMOG reduction [Ref. 11]

Three heated oxygen sensors


Direct ozone reduction, or DOR, pertains to vehicle radiator coatings and not the powertrain

API06 2012 Toyota Camry

3.5L “VVT-i” V-6 engine Power: 268hp@6200rpm, Torque: 248lb-ft@4700rpm Sequential Multi-Port Fuel Injection 24 valve, DOHC variable valve timing

Two heated air-fuel ratio sensors

Two heated oxygen sensors

Three way catalysts: two close coupled catalysts, one underbody catalyst


Page 12

6.0 Preparation for Testing

6.1 Catalyst and Sensor Aging

New catalytic convertors and exhaust system sensors were procured for all vehicles and aged on an engine test stand to the equivalent of 120,000 to 150,000 miles. All exhaust parts used for aging were stock and procured from authorized dealerships. Johnson Matthey Testing (JMT) in Taylor, Michigan provided the test protocol and performed the catalyst and sensor aging.

The engine test stand utilized an 8.1L Chevrolet V8 Engine with exhaust manifolds joined to a custom quad leg exhaust system (Figure 2). The engine exhaust was split into four legs to allow the aging of catalysts from multiple vehicles simultaneously. Exhaust sample feeds, thermocouples and flow controllers were instrumented into this system in their respective positions to support the precise control of the aging cycle.

Figure 2. Catalyst Aging on JMT Engine Stand: V-8 Engine (Top), Multi-leg Exhaust System (Bottom)

ExhaustFlow

API04Close Coupled Cat

API04Underbody Cat

API03Close Coupled Cat

API03Underbody Cat

VehicleSensors


Page 13

The catalysts from all six vehicles were aged in two dynamometer runs. Where possible, manufacturer hardware including interconnecting pipes, flex pieces and flanges were used in the test set-up. The characteristic length between the close coupled catalyst and underbody catalyst was maintained. The catalyst arrangement for each dynamometer run is summarized in Table 6. Exhaust system sensors were included in the aging process. Since the sensors had wires and plastic connectors in close proximity to the exhaust pipe, tube assemblies were designed to cool the sensors with shop air to avoid melting during this high temperature test (visible in Figure 2).

Table 6. Catalyst Arrangement for Engine Stand Aging Runs

Protocols to accelerate the aging of automotive catalysts on the engine test stand have been in use for many years and have evolved over time [Ref. 12,13,14]. The Rapid Aging Test, or RAT-A, utilizes a multi-mode sequence to produce elevated exhaust temperatures to thermally age the catalyst. Manufacturers have developed proprietary catalyst aging tests based on RAT-A to correlate the test results with real-world experience. For this study, it was not feasible to use proprietary aging cycles for each of the vehicle systems. The CARB-modified RAT-A cycle was chosen as a contemporary method for aging all vehicle systems in this study [Ref. 14]. The aging cycle parameters used were:

CARB Modified RAT-A: Four-Mode Aging

Mode 1 = 40 seconds engine out condition @ stoichiometric fuel-air ratio Inlet temperature @ 825°C (± 20°C) 80 scfm exhaust flow per converter

Mode 2 = 6 seconds @ fuel-rich operation 3.0% CO (± 0.3%).

Mode 3 = 10 seconds @ fuel-rich operation (same as Mode 2) with secondary air injection 3.0% O2 (± 0.3%).

Mode 4 = 4 seconds engine out condition @ stoichiometric fuel-air ratio Secondary air injection operation (same as Mode 3)

225 hours cycle time, equivalent to 120,000 to 150,000 miles The exhaust system included laboratory sensors for controlling the engine test stand. Typical exhaust system instrumentation is shown in Figure 3. Note that K-type thermocouples (designated as “TC”) were inserted radially through the can, one inch from the front face and rear face of the substrate per standard industry practice. An alcohol-free gasoline with 91 antiknock index was used for the catalyst aging tests. Several batches of fuel were used during the aging period, and fuel properties for each batch are summarized in Appendix 11.3. Aging fuel sulfur content varied from 18.5 to 43 ppm.

Exhaust

LegEngine Stand Aging Run #1 Engine Stand Aging Run #2

1 API01 Close Coupled Cat, API01 Underbody Cat API03 Close Coupled Cat, API03 Underbody Cat

2 API02 Close Coupled Cat API04 Close Coupled Cat, API04 Underbody Cat

3 API06 Left Bank Close Coupled Cat, API06 Underbody Cat API05 Close Coupled Cat, API05 Underbody Cat

4 API06 Right Bank Close Coupled Cat None


Page 14

Figure 3. Typical Exhaust System Instrumentation for Catalyst Aging Test

Precise control of air fuel ratio and secondary air injection is critical to ensure proper catalyst aging. Exposure to excessive exhaust temperatures may potentially cause non-reversible thermal deactivation of the catalyst coating, and such damage would not be representative of real world use. A complete record of the air-fuel ratio (AFR), catalyst inlet and bed temperatures was recorded to allow analysis of the thermal exposure. Histogram data are presented for API01 Malibu in Figures 4 and 5. Exhaust and catalyst temperature histogram data are provided for all vehicles in the Appendix 11.4. Distinct air-fuel ratios for each of the four modes of the CARB modified RAT-A cycle are apparent in the AFR histogram (Figure 4). The data confirm the exhaust inlet temperature was held to 825°C for a majority of the test cycle, as expected since Mode 1 is longest in duration (Figure 5, top). Temperature was hottest near the front face of the close coupled catalyst, due to an exothermic reaction of the exhaust gas. A peak temperature measurement of 1015°C was reached during the aging cycle.

Figure 4. Air-Fuel Ratio Histogram for Vehicle API01 over the 225 hour Aging Run

0

10

20

30

40

50

60

70

80

90

100

12

.0

12

.2

12

.4

12

.6

12

.8

13

.0

13

.2

13

.4

13

.6

13

.8

14

.0

14

.2

14

.4

14

.6

14

.8

15

.0

15

.2

15

.4

15

.6

15

.8

16

.0

16

.2

16

.4

16

.6

16

.8

17

.0

17

.2

17

.4

17

.6

17

.8

18

.0

Ho

urs

at

AF

R

AFR


Page 15

Figure 5. Exhaust Inlet, Close Coupled Catalyst and Underbody Catalyst Temperature Histograms for Vehicle API01 over the 225 hour Aging Run

Median and peak catalyst exposure temperatures are summarized in Table 7. Vehicle API03 and API05 (Sonata and A3, respectively) had the highest exposure temperatures. Vehicle API02 (Civic) had significantly lower exothermic reaction at the CCC front bed location. The close coupled catalyst temperature results for vehicle API06 (Camry) pertain to the left bank of the V6 engine.

0

10

20

30

40

50

60

70

80

90

100

CCC Inlet

0

10

20

30

40

50

60

70

80

90

100

Hours

at Tem

pera

ture CCC Front Bed

0

10

20

30

40

50

60

70

80

90

100

750

760

770

780

790

800

810

820

830

840

850

860

870

880

890

900

910

920

930

940

950

960

970

980

990

1000

1010

1020

1030

1040

1050

Temperature (°C)

UBC Front Bed


Page 16

Table 7. Median and Peak Catalyst Exposure Temperatures over Aging Period (225 hours)

6.2 Chassis Dynamometer Lab and Emissions Measurement

Emissions tests were performed in certification-compliant emissions laboratories at SGS Environmental Testing Corporation in Aurora, Colorado (Figure 6). All tests were run on Site 2, featuring a Burke Porter 48” roll dynamometer in a temperature and humidity controlled environment. The laboratory has a constant volume sampling system (CVS), raw modal and dilute bag gas sampling and analysis. The emission sampling arrangement is shown in Figure 7.

Figure 6. API02 Civic in SGS-ETC Site 2 Chassis Dynamometer Emissions Lab

Median Peak Median Peak

Vehicle Make Temperature Temperature Temperature Temperature

API01 Malibu 859 1015 791 850

API02 Civic 853 955 NA NA

API03 Sonata 891 1035 809 895

API04 Focus 868 1025 809 895

API05 A3 891 1015 823 895

API06 Camry 865 1005 788 870

Close Coupled Catalyst

Front Bed Temperature (°C)

Underbody Catalyst



Page 17

Figure 7. Emissions Sampling Arrangement

Vehicle API06 was equipped with a V6 engine. The continuous raw stream exhaust samples were drawn from both banks at the engine-out and intermediate locations. The raw stream emissions presented in this report therefore represent the combined emissions from both banks of the engine.

The following equipment was used to ensure accurate measurement of the very low emission concentrations expected from these vehicles:

Bag samples were simultaneously collected from the diluted vehicle exhaust and from the ambient, to ensure quantification of the background, and accurate calculation of cycle average exhaust mass emissions. Bag gas analysis included measurement of CO, CO2, NOx, total HC, and CH4.

NMHC was equal to the FID total hydrocarbons minus the response factor-corrected methane. Methane measurement was by gas chromatograph FID.

Continuous raw tailpipe emissions were measured to provide information on the time to catalyst light-off, and also to provide redundant information for bag-to-modal mass comparisons. This bag-to-modal mass correlation served as a quality check for each test.

Continuous engine-out raw emissions were measured to provide information on catalyst conversion efficiency. The test site used three raw sample streams to determine catalyst conversion efficiency for close coupled and underbody catalysts.

EEPS

MSS

CPC

PM2.5µm

cyclone

(heated)

CVS Tunnel

Bags

PM Filter

(heated)

Close Coupled CatUnder Body Cat

Raw Tailpipe Raw Intermediate Raw Engine Out

2nd Dil

1st Dil


Page 18

Low range analyzers and low concentration span gas bottles were used to ensure appropriate analyzer response and resolution, per normal operating practice.

Fuel consumption was calculated using the carbon balance method, accounting for actual mass % of carbon, hydrogen and oxygen in the fuel. Fuel economy was calculated using the “uncorrected method”. The corrected calculation for MPG, per 40CFR600.113-08(h)(1), was not applicable for oxygenated fuels used in the study.

Speciation of the exhaust gas for NMOG determination was beyond the scope of this study. NMOG mass emissions were estimated using a formula from an experimental correlation [Ref. 15]:

NMOGEST = (%EtOH * 0.0071 + 1.0302) * NMHC

where %EtOH was vol% ethanol in fuel. NMOG results presented in this report were estimated using this formula. For gasoline containing 10%vol ethanol, NMOGEST = 1.1012 * NMHC.

The effect of sulfur on particulate matter and particle number emissions was of interest, especially with the inclusion of GDI-equipped vehicles in the study. The entire exhaust volume was diluted in a full dilution tunnel (Figure 7) for the purposes of particulate matter measurement.

The primary mass measurement for the study was made using an AVL483 photo acoustic microsoot sensor (MSS). This instrument sampled from the CVS tunnel to minimize thermophoretic deposition losses. The instrument only measures the soot fraction (elemental carbon fraction) of the total particulate matter. The instrument is very sensitive, with a measurement resolution of ≤ 0.01 mg/m3.

Particulate matter (PM) samples were taken on Teflo 47mm filter media using a 40CFR Part 1065 compliant particulate matter sampler. Filters were processed in a temperature and humidity controlled clean room equipped with electrostatic charge neutralizers and a Mettler Toledo UMX2 microbalance. PM filter loading was commonly under 20µg for Phase 2 and Phase 3 of the FTP75 cycle, and not as repeatable as the microsoot sensor instrument. PM measurements were made primarily to estimate of the elemental carbon fraction of the total particulate matter. Particle Number (PN) measurements were made using equipment compliant to the Euro 6 PMP GPRE specification. Diluted exhaust samples were extracted from the CVS and coarse particles removed with a cyclone. The sample was further diluted using a Matter Engineering rotating disk diluter, and then passed through a thermodenuder (300°C evaporation tube) to remove nuclei mode volatile and sulfate aerosols. Second stage dilution was used to prevent re-condensation. Particle number measurement was made using a TSI Model 3790 Condensation Particle Counter (CPC). The CPC has a 23nm D50 cutoff. Only accumulation mode solid particles were counted.

Particle size distribution (PSD) was measured with a TSI Model 3090 Engine Exhaust Particle Sizer (EEPS) spectrometer. The data was used primarily to verify the removal of nuclei mode particles. The EEPS performs particle size classification based on differential electrical mobility classification. Charging of the aerosol is accomplished through two unipolar diffusion chargers. The charged particles are collected on electrically isolated electrodes located at the outer wall, and the PN concentration is determined by measuring the electrical current collected. An inversion algorithm is used to de-convolute the data, converting currents from the electrometers into 32 channels of output. This process allows the maximum resolution of the instrument to be represented by output channels that are equally spaced on a log scale between 5.6 nm and 560 nm. PN data was collected at a sampling rate of 1 Hz over the entire


Page 19

test cycle. The EEPS sampled from the same evaporation tube and diluter system used for the CPC. The EEPS also produced total particle number counts, but the data is less reliable than the CPC in part due to electrometer noise at low particle concentrations.

Statement on Testing at High Altitude

SGS Environmental Testing Corporation is located in Aurora, Colorado, at 5440 feet elevation above sea level. SGS-ETC performs emissions certification tests for vehicle and engine manufacturers, at local altitude and at other altitudes by employing altitude simulation equipment.

For this present study, the data analysis is focused on making relative comparison of vehicle emissions when tested on fuels having different sulfur content. The relative trends from this study are expected to be representative of results obtained at lower altitudes. Modern vehicles employ speed-density or MAF-based engine control systems that have compensation for barometric pressure. Under closed loop operation, fuel-air stoichiometry is controlled ensuring exhaust and catalyst temperatures are comparable at different altitudes. Under hard acceleration open loop operation, vehicles employ long term fuel trim (LTFT) adaptation for fuel enrichment and catalyst thermal protection. Because of these control strategies, exhaust and catalyst temperatures are comparable at different altitudes. This point is illustrated by comparing the catalyst bed temperatures for the 2009 Malibu. The same vehicle model was tested at SGS-ETC (5440 feet) and in Auburn Hills, Michigan (960 feet) [Ref. 5]. Close coupled catalyst front bed temperatures were in general agreement for the FTP75 and more aggressive US06 driving cycles (Figures 8 and 9, respectively). Exact thermocouple placement was not assured for this comparison.

Figure 8. Catalyst Bed Temperatures for 2009 Malibu at 5440 feet and 960 feet Elevation – FTP75


Page 20

Figure 9. Catalyst Bed Temperatures for 2009 Malibu at 5440 feet and 960 feet Elevation – US06

6.3 Vehicle Preparation and As-Received Exhaust Emissions

Road load derivations were performed on the Burke Porter dynamometer per SAE J2264. The equivalent test weights and road load coefficients used for the study are provided in Appendix 11.5.

The oil and oil filter were changed on each vehicle prior to the start of testing. Motor oils meeting manufacturer recommended specifications were used (Appendix 11.6). The study required using the same brand of motor oil for all vehicles. Since some oil viscosities were only available in a synthetic formulation, Mobil 1 synthetic oil was used. Some of the motor oils were very light viscosity and had the potential to impact hydrocarbon emissions measurement. To condition the oil following the oil change, each vehicle was run for at least two consecutive Standard Road Cycles.

The vehicles were tested in the as-received condition, to establish emissions for the factory original catalysts at low miles. The starting vehicle mileage is provided in Table 5. Federal certification gasoline (40CFR86.113-04) was used for these as-received emissions tests only, because the California LEV III fuel was not available at the time of testing. The test sequence was:

Drain and 40% refill

Four LA4 prep cycles

Drain and 40% refill

12 to 24 hour soak

FTP75 3-bag emissions test, bag only As-received vehicle emissions results are shown in Table 8. The vehicle emissions were compared to the most stringent standard that applied for that vehicle model (California SULEV-II, except for API06 certified to Federal Tier 2 Bin 5). This comparison was made to verify the selected vehicles were representative of properly operating vehicles in the fleet. NOx, CO and NMOG emissions were all below


Page 21

the applicable emissions standard. NMOG emissions were very near to the standard for vehicles certified to SULEV-II. This trend may partly be explained because the “as-received” emissions tests performed differed from the certification procedure:

Federal Tier 2 certification gasoline was used, rather than oxygenated California Phase 2 fuel. Oxygenated gasoline has been shown to lower NMHC and CO for some late model vehicles [Ref. 16, 17]

No canister load was performed

NMOG emissions were estimated from NMHC, per Section 6.2

NMHC and estimated NMOG emissions were very close in value and appear indistinguishable in Table 8 because Federal Tier 2 certification gasoline contains no oxygenate.

Table 8. As-Received Vehicle Exhaust Emissions, FTP75, Federal Certification Gasoline

The factory original exhaust system was then removed for each vehicle and replaced with the catalyst and sensor components that were aged on the engine stand (Section 6.1). Additional instrumentation was added to measure exhaust gas temperatures, and to allow for raw exhaust gas sample extraction for emissions measurement. Typical instrumentation used for the vehicle test is shown in Figure 10.

Figure 10. Typical Exhaust System Instrumentation for Vehicle Emissions Tests

NOx CO HC CH4 NMHC Est NMOG MPG

API01 - 2009 Malibu 0.008 0.678 0.012 0.004 0.009 0.009 24.32

SULEV II Standard @ 150k miles 0.020 1.000 -- -- -- 0.010 --

API02- 2012 Civic 0.006 0.141 0.010 0.002 0.008 0.008 34.52


API03 - 2012 Sonata 0.007 0.206 0.008 0.001 0.007 0.007 26.64


API04 - 2012 Focus 0.009 0.037 0.008 0.001 0.007 0.007 31.62


API05 - 2012 A3 0.011 0.318 0.012 0.005 0.008 0.008 27.51


API06 - 2012 Camry 0.021 0.093 0.012 0.002 0.010 0.010 25.6

T2 B5 Standard @ 50k miles 0.050 3.400 -- -- -- 0.075 --

FTP75 Weighted Bag Emissions (g/mile)


Page 22

7.0 Sulfur Reversibility Study – Individual Vehicle Test Results

Exhaust emissions and fuel economy results are shown for individual vehicles in Figures 11 to 16. These charts display the results weighted over the three phases for the FTP75 emissions test cycle. Gaseous emissions were determined from bag analysis. Soot and particle number emissions were measured by drawing continuous samples from the primary dilution tunnel.

There were ten data points for each reversibility sequence run: four baseline tests run on 10 ppm sulfur fuel, three tests using 80 ppm fuel, and three tests after the vehicle was switched back to 10 ppm fuel (Section 3). These ten test results are shown sequentially in the Figures 11 to 16, from left to right. For each of these three segments of data, the mean value is shown as a horizontal line. The vertical scales for these charts were chosen to magnify the results to identify small changes in emissions, in favor over keeping the scales the same for all vehicles. In this section, observations are made regarding emissions trends before, during and after the 80 ppm fuel exposure. Owing to the considerable variability within each group of data, some of the observed trends discussed in this section may not be statistically significant. A statistical analysis of the reversibility effects was performed using the FTP75 weighted data in Section 8, to draw conclusions about individual vehicles and the test fleet of six vehicles.

Gaseous mass emissions were also determined using continuous raw exhaust stream measurements taken at the engine-out, between catalyst, and tailpipe locations. This data was used to quantify the conversion efficiencies of the close coupled and underbody catalysts. The raw exhaust emissions and catalyst efficiency data were of secondary interest for this study, but the interested reader may gain some important insights regarding catalyst light-off, catalyst system behavior, and sources of emissions variability (Sections 7.7 and 7.8, Appendix 11.7 and 11.8).

A representative report of soot, particle number and particle size distribution is provided for each of the vehicles run on 10 ppm and 80 ppm sulfur fuels in Appendix 11.9. The same color contour scale was used for all color contour plots presented, to allow visual comparison. There is currently no certification standard for automotive particle number emissions in the United States. The Euro 6 PN standard of 6.0x1011 #/km (9.7x1011 #/mile), which begins for some GDI vehicle weight classes in September 2014, provides some perspective on future PN emissions levels. It is noted that Euro 6 PN standard applies to the NEDC cycle. Therefore a strict comparison of these results to the Euro 6 standard is not appropriate because the NEDC is a geometric based cycle with fewer transient maneuvers than the FTP75.


Page 23

7.1 API01 2009 Chevrolet Malibu

Emissions results for the 2009 Malibu fitted with aged catalysts and sensors are shown in Figure 11. NMOG and NOx emissions appeared to increase with each subsequent emissions test run on 80ppm sulfur fuel. For the third test run on 80ppm fuel, NMOG and NOx emissions exceeded the SULEV-II emissions standards of 0.01 and 0.02 g/mile, respectively. Following the change back to 10 ppm sulfur fuel, mean NMOG emissions were just below the baseline mean value indicating the sulfur effects on NMOG were reversible. NOx emissions dropped more gradually during the subsequent recovery tests performed following the switch to 10 ppm fuel, with the final test result having NOx emissions below the baseline NOx levels.

NOx emissions more than doubled when this vehicle was run on 80 ppm fuel, relative to the baseline. NOx emissions from this vehicle responded to fuel sulfur changes differently than other vehicles in the study.

There was no observed change in mean CO emissions during and after 80 ppm sulfur fuel exposure. Soot mass and PN emissions showed increases during and after the 80 ppm fuel exposure, but the emissions were at very low levels for this SFI-equipped vehicle. The variability of the soot and PN data was considered in Section 8 to conclude that the differences in the means before and after 80ppm fuel exposure were not statistically significant.

The first baseline test point showed higher CO and soot emissions than all other tests. The test met quality assurance criteria and the result remained in the dataset for statistical analysis. No soot measurement was available for the third test using 80 ppm sulfur fuel due to instrument malfunction.

The soot fraction of total PM was estimated to be 56% for the reversibility sequence performed. The highest PM measurement for the vehicle was 1.1 mg/mile (corresponding to the first baseline test in Figure 11), far below the 10 mg/mile emissions standard.

The 2009 Malibu was chosen for this study to allow a comparison with previous published results [Ref. 5]. A comparison of the catalyst conversion efficiency, raw tailpipe emissions, and discussion is provided in Section 7.9.


Page 24

Figure 11. Sulfur Reversibility Test Results, API01 Malibu

API01

0.006

0.008

0.01

0.012

gram

s/m

ile

NMOG

0

0.01

0.02

gram

s/m

ile

NOx

0

0.2

0.4

0.6

0.8

gram

s/m

ile

CO

24

24.5

25

25.5

26

Mile

s p

er

Gal

lon

Fuel Economy

0.2

0.3

0.4

0.5

0.6

mg/

mile

Soot

5.0E+11

1.0E+12

1.5E+12

#/m

ile

Test Sequence

Particle Number

10ppm Baseline 80ppm 10ppm Reversibility Average


Page 25

7.2 API02 2012 Honda Civic EX

Emissions results for the 2012 Civic fitted with aged catalysts and sensors are shown in Figure 12. All weighted NMOG emission results exceeded the SULEV-II emissions standard of 0.01 g/mile for the vehicle equipped with the aged catalyst, using both 10 ppm and 80 ppm sulfur fuels. NMOG emissions for some tests approached 0.02 g/mile, nearly double the standard. NOx and CO emissions were under the SULEV-II standards.

The mean NMOG, CO and NOx emissions all increased for 80 ppm fuel tests, compared to the baseline emissions performed using 10 ppm fuel. Following the change back to 10 ppm sulfur fuel, mean NMOG, NOx and CO emissions were just below the baseline mean value indicating the sulfur effects on emissions were reversible.

The highest PM measurement for the vehicle was 1.3 mg/mile, far below the 10 mg/mile emissions standard. The soot fraction of total PM was estimated to be 45% for the reversibility sequence performed. Soot mass and PN emissions were at very low levels for this SFI-equipped vehicle. There were only very slight changes to mean soot and PN emissions during and after 80 ppm sulfur fuel exposure.


Page 26

Figure 12. Sulfur Reversibility Test Results, API02 Civic

API02

0.01

0.015

0.02

0.025

gram

s/m

ile

NMOG

0

0.01

0.02

gram

s/m

ile

NOx

0

0.1

0.2

0.3

0.4

0.5

mg/

mile

Soot

0.0E+00

5.0E+11

1.0E+12

1.5E+12

#/m

ile

Test Sequence

Particle Number


0

0.1

0.2

0.3

gram

s/m

ile

CO

33

33.5

34

34.5

35

Mile

s p

er

Gal

lon

Fuel Economy


Page 27

7.3 API03 2012 Hyundai Sonata

Emissions results for the 2012 Sonata fitted with aged catalysts and sensors are shown in Figure 13. Most weighted NMOG emission results exceeded the SULEV-II emissions standard of 0.01 g/mile, when the vehicle was run on 10 ppm and 80 ppm fuels using the aged catalyst. NMOG emissions appeared to increase with each subsequent emissions test run on 80ppm sulfur fuel, peaking at 0.020 g/mile for the third test. The NMOG emissions had high “within group” variability, meaning the variability was quite large for consecutive tests performed on the same fuel. The variability in NMOG emissions is attributed to catalyst performance. Engine-out emissions were relatively constant for consecutive tests by comparison (Appendix 11.8), and had a considerably lower coefficient of variation than post-catalyst emissions as further discussed in Section 7.8. The variation in catalyst performance does not appear due to thermal differences, since engine exhaust and catalyst temperature profiles were very repeatable for the tests run (Appendix 11.7).

All NOx and CO emissions results were well under the SULEV-II standards. Combined NMOG+NOx emissions were under the proposed Tier 3 Bin 30 standard of 0.03 g/mile for both 10ppm and 80ppm sulfur fuels.

The mean NMOG, CO and NOx emissions all increased for 80 ppm fuel tests, compared to the baseline emissions performed using 10 ppm fuel. Following the change back to 10 ppm sulfur fuel, mean NMOG, NOx and CO emissions decreased relative to the 80 ppm fuel results, but remained slightly higher than the baseline results run with 10 ppm fuel. The variability of the data has a bearing on determining if the mean values before and after 80 ppm fuel exposure are statistically equivalent, and is discussed in Section 8.

Vehicle API03 was equipped with a GDI engine. This vehicle produced the highest PM, soot and particle number emissions compared to other vehicles in the study. Nevertheless, PM emissions were below SULEV-II mass standards. The highest PM measurement for the vehicle was 6.3 mg/mile, below the 10 mg/mile emissions standard. The soot fraction of total PM was estimated to be 71% for the reversibility sequence performed.

Soot and particle number emissions were highest during the first hill in Phase 1 of the FTP75, but emissions were also evident during transient maneuvers even after the catalyst warm-up (Appendix 11.9).

This vehicle’s PM, soot and PN emissions were all found to be sensitive to 80 ppm fuel. Mean soot and PN emissions increased by 11% and 17% respectively when using 80 ppm fuel, relative to the baseline results. Following the change back to 10 ppm sulfur fuel, mean soot and PN emissions were just below the baseline mean value indicating the sulfur effects on emissions were reversible.


Page 28

Figure 13. Sulfur Reversibility Test Results, API03 Sonata

API03

0.005

0.01

0.015

0.02

0.025

gram

s/m

ile

NMOG

0

0.005

0.01

0.015

gram

s/m

ile

NOx

3.0

3.5

4.0

4.5

mg/

mile

Soot

4.0E+12

5.0E+12

6.0E+12

7.0E+12

#/m

ile

Test Sequence

Particle Number


0

0.1

0.2

0.3

gram

s/m

ile

CO

26

26.5

27

27.5

28

Mile

s p

er

Gal

lon

Fuel Economy


Page 29

7.4 API04 2012 Ford Focus

Emissions results for the 2012 Focus fitted with aged catalysts and sensors are shown in Figure 14. There are two complete reversibility test sequences shown on each chart. The left set designated as the “Initial Sequence” is discussed first.

Initial Sequence NMOG and CO emissions were found to be sensitive to the 80 ppm fuel. When run on 80 ppm fuel, the vehicle produced mean NMOG and CO emissions that were 16% and 77% higher, respectively, compared to results using the 10 ppm baseline fuel. The coefficient of variation for NMOG and CO emissions were quite large compared to engine-out emissions, and compared to tailpipe emissions from other vehicles in the study (Section 7.8). This emissions variability was isolated to the catalyst performance, as it occurred despite the relatively constant engine-out emissions (Appendix 11.8), and comparable catalyst temperature profiles for the tests run (Appendix 11.7).

The vehicle’s mean NMOG and CO emissions both showed good reversibility when the vehicle was switched back to 10 ppm sulfur fuel, following the 80 ppm fuel exposure. For the Initial Sequence, mean NOx emissions did not change appreciably during or after the 80 ppm fuel exposure.

This vehicle was equipped with a GDI engine. PM, soot and PN emissions were higher than those measured from the SFI-equipped vehicles in the study as expected. The highest PM measurement for the vehicle was 2.6 mg/mile, well below the 10 mg/mile PM emissions standard. The soot fraction of total PM was estimated to be 62% for the reversibility sequence performed. Soot and particle number emissions peaked in Phase 1 of the FTP75, but emission peaks were also evident during accelerations even after the catalyst warm-up (Appendix 11.9).

The mean values for soot and PN emissions increased during testing with 80 ppm sulfur fuel, and remained at that elevated level following the switchback to 10 ppm fuel. After deeper examination of the data, this behavior was not believed to be a fuel sulfur effect but rather was due to poor repeatability in this vehicle’s soot and PN emissions (Section 8.2).

Repeat Sequence The entire reversibility test sequence was repeated for vehicle API04, in order to further investigate the sensitivity and reversibility of soot and PN emissions to fuel sulfur. The dataset located at right in Figure 14 is designated the “Repeat Sequence” and further discussed here.

Upon retest, very different observations were made regarding the sensitivity of vehicle soot and PN emissions to fuel sulfur. In the retest, there was no statistical difference in the means at the baseline, 80 ppm fuel exposure, and 10 ppm fuel recovery segments of the test sequence. The variation of the soot and PN data is further discussed in Section 8.2.

NMOG emissions were just over the SULEV-II standards for two of the emissions tests, whereas NOx and CO emissions were well within the standards. Combined NMOG+NOx emissions were under the proposed Tier 3 Bin 30 standard of 0.03 g/mile for both 10ppm and 80ppm sulfur fuels. Following the change back to 10 ppm sulfur fuel, mean NMOG, NOx and CO emissions were just below the baseline mean values indicating the sulfur effects on emissions were reversible. Regarding the statistical analysis of gaseous emissions, the conclusions drawn from the Initial Sequence and Repeat Sequence were identical (Section 8.2).


Page 30

Figure 14. Sulfur Reversibility Test Results, API04 Focus

API04

0.005

0.01

0.015

gram

s/m

ile

NMOGInitial Sequence Repeat Sequence

0

0.005

0.01

0.015

gram

s/m

ile

NOx

0

0.5

1

1.5

mg/

mile

Soot

2.0E+12

3.0E+12

4.0E+12

#/m

ile

Test Sequence

Particle Number


0

0.1

0.2

0.3

gram

s/m

ile

CO

31.5

32

32.5

33

33.5

Mile

s p

er

Gal

lon

Fuel Economy


Page 31

7.5 API05 2012 Audi A3

Emissions results for the 2012 Audi A3 fitted with aged catalysts and sensors are shown in Figure 15. NMOG emission results were near or just above the SULEV-II emissions standard of 0.01 g/mile for the vehicle equipped with the aged catalyst, using both 10 ppm and 80 ppm sulfur fuels. NOx emissions from a single test (the third test run on 80 ppm fuel) were over the emissions standard of 0.02 g/mile. All other NOx and CO emissions results were within the SULEV-II standards.

This vehicle was equipped with a turbocharged GDI engine. NMOG, CO, Soot and PN emissions were not sensitive to the change to 80 ppm sulfur fuel, so reversibility of vehicle emissions was not relevant for those species.

NOx emissions increased significantly for a single test run on 80 ppm fuel. Following the change back to 10 ppm sulfur fuel, mean NOx emissions were the same as the baseline mean values indicating the sulfur effects on NOx emissions were reversible.

The highest PM measurement for the vehicle was 2.8 mg/mile, well below the 10 mg/mile emissions standard. The soot fraction of total PM was estimated to be 59% for the reversibility sequence performed.


Page 32

Figure 15. Sulfur Reversibility Test Results, API05 A3

API05

0.005

0.01

0.015

gram

s/m

ile

NMOG

0

0.01

0.02

0.03

0.04

gram

s/m

ile

NOx

0

0.5

1

1.5

mg/

mile

Soot

2.0E+12

3.0E+12

4.0E+12

5.0E+12

#/m

ile

Test Sequence

Particle Number


0

0.2

0.4

0.6

0.8

gram

s/m

ile

CO

26

26.5

27

27.5

28

Mile

s p

er

Gal

lon

Fuel Economy


Page 33

7.6 API06 2012 Toyota Camry

Emissions results for the 2012 Camry fitted with aged catalysts and sensors are shown in Figure 12. NMOG, NOx and CO emissions were far under the Federal Tier 2 Bin 5 standards that apply to this vehicle, for all fuels tested. The Camry emissions test results were more repeatable than other vehicles in the study.

NMOG, NOx and CO emissions test results peaked for the first emissions test performed following 300 miles of conditioning on the chassis dynamometer using 80 ppm fuel. The US06 cycle run between emissions tests appeared to effectively reduce the sulfur effects on gaseous emissions for subsequent tests using 80 ppm fuel. The emissions from this vehicle therefore appeared to have some sensitivity to the 80ppm fuel, but it is postulated that the effects may not be as apparent for aggressive driving applications.

Following the change back to 10 ppm sulfur fuel, mean NMOG, NOx and CO emissions were at or just below the baseline mean value indicating the sulfur effects on emissions were reversible.

The highest PM measurement for the vehicle was 0.6 mg/mile, far below the 10 mg/mile emissions standard. The soot fraction of total PM was estimated to be 33% for the reversibility sequence performed.

This SFI-equipped vehicle has the lowest PM, soot and PN emissions of all vehicles in the study. The change to mean soot and PN emissions was negligible during and after 80 ppm sulfur fuel exposure.


Page 34

Figure 16. Sulfur Reversibility Test Results, API06 Camry

API06

0

0.01

0.02

0.03

0.04

gram

s/m

ile

NMOG

0

0.01

0.02

0.03

gram

s/m

ile

NOx

0

0.1

0.2

0.3

0.4

0.5

mg/

mile

Soot

0.0E+00

5.0E+11

1.0E+12

1.5E+12

#/m

ile

Test Sequence

Particle Number


0

0.2

0.4

0.6

0.8

gram

s/m

ile

CO

25.5

26

26.5

27

27.5

Mile

s p

er

Gal

lon Fuel Economy


Page 35

7.7 Comparison of Vehicle Exhaust Temperatures and Emissions

A key aspect of the study was to ensure a proper sulfur purge occurred to condition the catalysts at the start of the reversibility test sequence. The EPEFE cycle [Ref. 7] was used to accomplish the catalyst sulfur purge. The EPEFE cycle included a series of ten wide open throttle accelerations to increase catalyst operating temperature. During WOT acceleration, most vehicles use open loop fueling control to command rich combustion for catalyst thermal protection. A segment of the EPEFE cycle shown in Figure 17 illustrates the fuel enrichment, exhaust gas temperature and catalyst front bed temperature during the WOT event.

Figure 17. Segment of the EPEFE Cycle Used for Catalyst Sulfur Purge

Typical peak operating temperatures for the WOT event are compared for the vehicles in Table 9. The exhaust gas temperature exceeded the criteria of 700°C for all vehicles without resorting to artificial means such as increasing the dyno roll load. The temperatures for vehicle API01 were substantially hotter than the other vehicles. For vehicle API06, the close coupled catalyst temperatures in the following tables correspond to the left bank of the V6 engine.

Table 9. Typical Exhaust Gas and Catalyst Bed Temperatures for EPEFE Cycle WOT Events

The reversibility test sequence used in this study included alternating US06 and FTP75 cycles, to encompass both higher speed and lower speed vehicle operation (Section 3). The US06 cycle has higher exhaust temperatures than the FTP75, and therefore may play a role in reversing the catalyst sulfur poisoning effect depending on the vehicle technology. A comparison of US06 and FTP75 median and

Typical WOT Conditions API01 API02 API03 API04 API05 API06 Criteria

CC Catalyst Inlet Temp (°C) 854 788 782 788 754 777 >700

CC Catalyst Front Bed Temp (°C) 888 838 843 838 810 849

UB Catalyst Front Bed Temp (°C) 771 -- 766 777 760 721

Lambda 0.76 0.87 0.77 0.83 0.82 0.88 < 1.0


Page 36

peak catalyst temperatures is provided in Table 10. This table illustrates a balance in vehicle operation over the reversibility test sequence. For about 75% of the time the vehicle was operated on the longer duration FTP75 cycle with speed averaging 21.2 mph. For the remaining 25% of time, the vehicle was operated over the US06 cycle averaging 48.4 mph, and the median CCC front bed temperature increased by about 140 to 180°C relative to the FTP75 depending on the vehicle technology.

Table 10. Median and Peak Catalyst Temperatures for the US06 and FTP75 Cycles, 10ppm Sulfur Fuel

A comparison of catalyst warm-up temperatures and catalyst light off is shown for the first phase of the FTP75 test in Figure 18. Vehicle API03 had the fastest warm-up of engine-out exhaust gas. The manufacturer claims to use a late fuel injection strategy to promote fast catalyst light off and this does appear to be the case as tailpipe NOx emissions were very low for this vehicle in comparison to other vehicles (Figure 18, bottom).

Vehicle API01 had the fastest warm-up of the catalyst front bed temperature. This vehicle was equipped with secondary air injection and employed rich operation at startup to promote fast catalyst light-off [Ref. 5].

Catalyst warm-up and tailpipe NOx emissions are shown for individual vehicles in Appendix 11.7. Representative data is shown for a baseline test on 10 ppm fuel, for an 80 ppm fuel test, and for a reversibility test returning to 10 ppm fuel. The catalyst temperatures were very repeatable for FTP75 tests regardless of fuel, suggesting that the differences in NOx emissions were not due to differences in substrate warm-up during testing.

US06 Cycle, Median and Peak Temperatures (US06 Duration=596 seconds, Average Speed=48.4 mph)

Test ID

Median

Temperature

Peak

Temperature

Median

Temperature

Peak

Temperature

Median

Temperature

Peak

Temperature

API01 Malibu 2110425 724 846 809 944 695 795

API02 Civic 2109139 603 757 735 859 -- --

API03 Sonata 2110626 695 839 804 932 697 806

API04 Focus 2110386 650 903 804 906 716 809

API05 A3 2110205 598 714 700 791 649 743

API06 Camry 2110109 603 699 721 847 556 633

FTP75 Cycle, Median and Peak Temperatures (FTP75 Duration=1877 seconds, Average Speed=21.2 mph)

Test ID

Median

Temperature

Peak

Temperature

Median

Temperature

Peak

Temperature

Median

Temperature

Peak

Temperature

API01 Malibu 2110445 569 713 654 845 506 610

API02 Civic 2109547 456 632 565 744 -- --

API03 Sonata 2110637 556 702 651 834 513 627

API04 Focus 2110397 469 601 621 752 492 610

API05 A3 2110229 463 558 552 711 496 570

API06 Camry 2109627 457 587 579 726 378 456

Vehicle Model

Engine Out

Temperature (°C)



Underbody Catalyst


Underbody Catalyst




ModelVehicle

Engine Out

Temperature (°C)


Page 37

Figure 18. Catalyst Warm-Up and NOx Light Off Comparison, 10ppm Sulfur Fuel

0

100

200

300

400

500

600

700

800

0 20 40 60 80 100 120

Tailp

ipe

NO

x (p

pm

)

Test Time (sec)

Tailpipe NOx Concentration

API01 API02 API03

API04 API05 API06

0

200

400

600

800

1000

Tem

pe

ratu

re (

°C)

UB Catalyst Bed Temp

API01 API03 API04

API05 API06

0

200

400

600

800

1000

Tem

pe

ratu

re (

°C)

CC Catalyst Bed Temp

API01 API02 API03 API04

API05 API06 Bank 1 API06 Bank 2

0

200

400

600

800

1000

Tem

pe

ratu

re (

°C) Engine Out Temp

API01 API02 API03 API04

API05 API06 Bank 1 API06 Bank 2


Page 38

Soot emissions are compared for the six vehicles tested using 10 ppm and 80ppm fuels in Figure 19. The soot concentrations were from measurements taken in the CVS dilution tunnel, with the same CVS flow used for all tests. Therefore, soot concentrations also represents continuous soot mass emissions, but are not to be compared with raw stream concentrations. All of the GDI-equipped vehicles emitted soot during the start-up and before the vehicle was shifted into drive (between 0 and 20 seconds). All vehicles produced measurable soot during the first acceleration. Vehicle API03 produced by far the highest soot emissions. Soot emissions decreased substantially upon vehicle warm-up.

Only vehicle API03 was conclusively found to have higher mean soot and particle number emissions on 80 ppm fuel compared to 10 ppm fuel. Vehicles equipped with GDI engines had about five to seven times higher soot mass and particle number emissions on average compared to the SFI-equipped vehicles.

A strong correlation existed between soot mass and PN emissions, as expected since both methods measured elemental carbon and excluded volatile organic and sulfate aerosols. Representative PN emissions and size distributions are reported for 10 ppm and 80 ppm fuels in Appendix 11.9. It is noted the same color contour scale was used for all color contour plots presented.

Figure 19. Soot Emissions Comparison in CVS Diluted Exhaust Stream, 10 and 80 ppm Sulfur Fuels


Page 39

7.8 Raw Emissions and Catalyst Efficiency Data

Raw exhaust stream measurements were taken at the engine-out, between catalyst, and tailpipe locations. This data was used to quantify the conversion efficiencies of the close coupled and underbody catalysts (Appendix 11.8). The raw exhaust emissions and catalyst efficiency data are of secondary interest for this study, but some observations regarding catalyst system behavior and sources of emissions variability are discussed in this section.

Conversion efficiency of hydrocarbon emissions was greater than 98% across the close coupled catalyst for all vehicles in the study. For all vehicles except API05, all of the hydrocarbon conversion occurred across the close coupled catalyst which is engineered for fast light-off, whereas comparatively little hydrocarbon conversion occurred across the underbody catalyst. Vehicle API05 was the only vehicle to have HC conversion across the underbody catalyst (Figure 20). The bars in the chart represent triplicate test results for the three segments of the reversibility test sequence: baseline tests using 10 ppm sulfur fuel, using 80 ppm fuel, and tests following the switch back to 10 ppm fuel.

Figure 20. Conversion of Hydrocarbons Across Close Coupled and Underbody Catalysts, Vehicle API05

The performance of close coupled catalysts and underbody catalysts varied substantially for different vehicles, reflecting the diversity of the vehicle technology chosen for study. Vehicle API03 had very repeatable engine-out emissions for the reversibility sequence, using both 10 ppm and 80 ppm fuels. The performance of the close coupled catalyst was found to be affected by the 80 ppm fuel and had lower NOx conversion efficiency (Figure 21, upper right). The NOx concentration entering the underbody catalyst was therefore higher for the 80 ppm fuel tests. But in contrast, the underbody catalyst NOx conversion efficiency was better for the tests with 80 ppm sulfur fuel. Underbody catalyst conversion efficiency improved for tests with higher inlet NOx concentrations (Figure 21, lower). Vehicle API03 appeared to have interdependency between the exhaust feed gas concentration and conversion efficiency, noting that catalyst temperatures were about the same for the tests (Appendix


Page 40

11.7). API04 exhibited similar behavior for some tests. These examples reinforce the importance of testing the complete vehicle system to evaluate sulfur reversibility effects, because misleading conclusions could be drawn from individual component results.

Figure 21. NOx Conversion Across Close Coupled and Underbody Catalysts, Vehicle API03

Some of the vehicles had quite substantial variations in gaseous emissions from bag analysis, as noted in Sections 7.1 to 7.6. There are many possible contributors to these variations, but principle contributors may be driver variation, measurement error at low emissions levels, engine variation and catalyst performance variation. A quality plan was implemented to control test-related variations: for instance, all tests were performed in the same chassis dynamometer laboratory and the same driver was used for all except two of the tests. Moreover, all tests presented in this report met quality control criteria for driver violations. There was evidence the variations seen in the emissions data were due to the vehicle itself, since procedural controls and quality checks were used to minimize laboratory sources of variation.

The raw emissions dataset was used to further explore the source of vehicle emissions variation. Mean values and standard deviations for engine-out, intermediate, and tailpipe emissions were tabulated for tests using 10 ppm sulfur fuel (7 total tests per vehicle). The coefficient of variation (COV=standard deviation/mean) were compared at these three locations in Table 11. The COVs for NOx, CO and HC were considerably smaller at the engine-out location for every vehicle in the study, relative to post-catalyst locations. This finding indicated the engine-out emissions were more repeatable (also shown in Appendix 11.8), suggesting the vehicle was being driven consistently on the dyno from test-to-test. Exhaust and catalyst temperatures, which are known to effect catalyst performance, were also very repeatable from test-to-test (Appendix 11.7). COVs were 3 to 17 times higher at the tailpipe location


Page 41

compared to engine-out, indicating the catalyst system was a large source of variability in the emissions data. Apparently, small variations in catalyst input parameters produced a large variation in tailpipe emissions results. The tailpipe emissions COVs for vehicles API01 and API03 were large in comparison to vehicles API05 and API06, suggesting the variability was a function of vehicle technology and was not dominated by measurement error.

Table 11. Coefficient of Variation for Raw Exhaust Emissions, FTP75, 10 ppm Sulfur Fuel

7.9 Comparison of API01 Malibu NOx Results with the Umicore Study

The 2009 Malibu SULEV-II PZEV was chosen for study in order to compare data with published results from Umicore [Ref. 5]. The Umicore study reported NOx emissions results for the underbody catalyst only.

The studies used the same specification vehicle, both equipped with dynamometer-aged aftertreatment systems. A comparison of catalyst aging and test fuels is shown in Table 12. The Umicore study used 33 and 3 ppm sulfur fuels, whereas the present study used 80 ppm and 10 ppm sulfur fuels to explore sulfur reversibility. Raw emissions measurements were made to determine catalyst conversion efficiency.

Vehicle ID

NOx Emissions Mean Stdev COV Mean Stdev COV Mean Stdev COV

API01 3.38 0.14 0.040 0.055 0.006 0.112 0.0071 0.0025 0.353

API02 2.73 0.09 0.033 -- -- -- 0.0074 0.0011 0.143

API03 2.55 0.06 0.024 0.016 0.004 0.264 0.0059 0.0007 0.121

API04 2.38 0.08 0.033 0.022 0.005 0.248 0.0065 0.0009 0.138

API05 2.58 0.03 0.010 0.087 0.019 0.217 0.0139 0.0019 0.140

API06 2.89 0.04 0.014 0.026 0.003 0.119 0.0213 0.0023 0.110

CO Emissions Mean Stdev COV Mean Stdev COV Mean Stdev COV

API01 10.83 0.31 0.028 0.871 0.236 0.271 0.3974 0.1953 0.491

API02 6.11 0.08 0.013 -- -- -- 0.1255 0.0248 0.198

API03 11.79 0.24 0.020 0.695 0.054 0.078 0.1589 0.0320 0.201

API04 11.19 0.38 0.034 0.357 0.032 0.089 0.1137 0.0179 0.157

API05 10.85 0.24 0.022 3.054 0.239 0.078 0.4076 0.0336 0.082

API06 11.91 0.18 0.015 0.426 0.050 0.117 0.2838 0.0305 0.107

HC Emissions Mean Stdev COV Mean Stdev COV Mean Stdev COV

API01 1.19 0.03 0.027 0.010 0.002 0.221 0.0119 0.0011 0.095

API02 1.51 0.03 0.023 -- -- -- 0.0190 0.0032 0.169

API03 1.74 0.06 0.033 0.010 0.003 0.298 0.0150 0.0043 0.287

API04 2.03 0.08 0.041 0.010 0.002 0.225 0.0104 0.0014 0.137

API05 1.71 0.04 0.023 0.017 0.020 0.018 0.0151 0.0014 0.095

API06 1.94 0.04 0.021 0.019 0.001 0.079 0.0267 0.0016 0.059

Engine-Out Intermediate Tailpipe


Page 42

Table 12. 2009 Malibu SULEV-II PZEV Fuel Sulfur Studies – Catalyst Aging and Test Fuels

There were some differences in the test protocol that may be identified through the review of Section 3 and [Ref. 5]. In both studies, triplicate FTP75 emissions tests were performed using a “high sulfur” fuel, and then triplicate tests were repeated following switchover to a “low sulfur” fuel. The NOx results from the studies are compared in Figure 22, with Umicore results on top and results from the present study on bottom.

Figure 22. 2009 Malibu NOx Emissions – Comparison between Umicore and API Fuel Sulfur Studies

The NOx emissions upstream of the underbody catalyst ranged from 25 to 48 mg/mile for the Umicore tests, and 46 to 63 mg/mile for the present study. The close coupled and underbody catalyst temperatures were comparable between the labs for the FTP75 emissions test and also for the US06 prep cycle that was run between emissions tests (Figures 8,9). The US06 cycle was not run between emissions tests when the 3 ppm fuel was run at Umicore (Figure 22b).

Umicore Study API Sulfur Effects Reversibility Study

Close Coupled

Catalyst Aging

Catalyst aged on dyno to 150,000 mile equivalent

4-mode aging cycle for 150 hours

Peak bed temperature = 1030°C

Catalyst aged on dyno to 120,000 to 150,000 mile equivalent



Underbody

Catalyst Aging

CC and UB catalysts aged for different durations



CC and UB catalyst aged in same set-up



Aging Fuel Not specifiedAlcohol-free gasoline with 91 antiknock index

Fuel sulfur content = 18.5 to 43 ppm

Emissions Test Fuel -

High Sulfur

CARB Phase II Certification Gasoline

11% vol MTBE nominal

Fuel sulfur content = 33 ppm

California LEV III Certification Gasoline

10% vol ethanol nominal

Fuel sulfur content = 80 ppm (by doping base fuel)

Emissions Test Fuel -

Low Sulfur

EEE-Lube Certification Gasoline

Alcohol free


California LEV III Certification Gasoline

10% vol Ethanol nominal



Page 43

The Umicore results show lower catalyst conversion efficiency and higher tailpipe NOx emissions for both 33 ppm and 3 ppm sulfur fuels, compared to 10 ppm fuel results from the present study. Baseline NOx emissions (Figure 22c), and stabilized results from tests run after the 80 ppm fuel exposure (Figure 22d) were below the stabilized NOx emissions measured at Umicore using 3 ppm fuel (Figure 22b).

Tests were run to investigate the sensitivity of the underbody catalyst to fuel sulfur ranging from 10 to 30 ppm. Stabilized emissions results, run in a randomized order, are shown in Figure 23. The comparison of NOx using 30 ppm fuel (Figure 23) to the stabilized NOx results using 33 ppm fuel from Umicore (Figure 22a Test 3) is favorable.

Figure 23. Sensitivity of API01 Underbody Catalyst NOx Conversion to Fuel Sulfur

The lowest underbody catalyst conversion efficiency was 73% from the present study, and occurred for the first test run using 80 ppm fuel (Appendix 11.8). By contrast, NOx conversion efficiency ranged from 42 to 56% for four of the six Umicore tests run using 33 and 3 ppm sulfur fuels (Figure 22). The “unstabilized” NOx emissions of 26 mg/mile (Figure 22a, Test 1) were considerably higher than NOx emissions measured using 80 ppm fuel in the present study. The reason for these discrepancies may be related to procedural differences leading up to the emissions tests, fuel differences, or catalyst aging differences noted in Table 12.

7.10 Reversibility Data Tables

The emissions and fuel economy data from the sulfur reversibility study are provided in Tables 13 to 16. The gaseous emissions were from bag analysis, and all results are weighted emissions over the FTP75 cycle. This dataset was used for the statistical analysis in Section 8.0.


Page 44

Table 13. Fuel Sulfur Reversibility Study Dataset for Analysis, API01 and API02

Step

Test Start Date

Control Number Fuel

WTD Bag THC GPM

WTD Bag CH4 GPM

WTD Bag

NMHC GPM

WTD Bag

NMOG GPM

WTD Bag NOx GPM

WTD Bag

NMOG +NOx GPM

WTD Bag CO

GPM

WTD Bag CO2 GPM

WTD Bag

ECON MPG

WTD MSS Soot

(mg/mi)

WTD CPC

Particle Number (#/mi)

Test Number

Odo- meter Driver

Test 0 1/28/2013 API01 CALEV3_10 0.0138 0.0059 0.0082 0.0090 0.0067 0.0157 0.8893 346.84 24.67 0.595 1.26E+12 2109151 11601 JREED

Test 1 1/29/2013 API01 CALEV3_10 0.0106 0.0035 0.0072 0.0080 0.0104 0.0183 0.3036 344.03 24.93 0.324 8.53E+11 2109166 11621 MWEDDINGTON





Test 3 2/6/2013 API01 CALEV3_80 0.0148 0.0047 0.0104 0.0114 0.0210 0.0324 0.4717 343.21 24.97 -- 1.12E+12 2109340 12046 MWEDDINGTON








Test 1 2/4/2013 API02 CALEV3_80 0.0212 0.0044 0.0170 0.0187 0.0095 0.0282 0.1929 248.44 34.53 0.372 5.87E+11 2109290 6870 JREED







Page 45

Table 14. Fuel Sulfur Reversibility Study Dataset for Analysis, API03

Step

Test Start Date

Control Number Fuel

WTD Bag THC GPM

WTD Bag CH4 GPM

WTD Bag

NMHC GPM

WTD Bag

NMOG GPM

WTD Bag NOx GPM

WTD Bag

NMOG +NOx GPM

WTD Bag CO

GPM

WTD Bag CO2 GPM

WTD Bag

ECON MPG

WTD MSS Soot

(mg/mi)

WTD CPC


Test Number

Odo- meter Driver









Test 2 2/20/2013 API03 CALEV3_10 0.0103 0.0019 0.0086 0.0094 0.0065 0.0160 0.1468 318.53 26.95 -- -- 2109578 8150 MWEDDINGTON



Page 46

Table 15. Fuel Sulfur Reversibility Study Dataset for Analysis, API04

Step

Test Start Date

Control Number Fuel

WTD Bag THC GPM

WTD Bag CH4 GPM

WTD Bag

NMHC GPM

WTD Bag

NMOG GPM

WTD Bag NOx GPM

WTD Bag

NMOG +NOx GPM

WTD Bag CO

GPM

WTD Bag CO2 GPM

WTD Bag

ECON MPG

WTD MSS Soot

(mg/mi)

WTD CPC


Test Number

Odo- meter Driver

API04 Initial Sequence








Test 1 2/21/2013 API04 CALEV3_10 0.0107 0.0022 0.0087 0.0095 0.0059 0.0154 0.1699 269.07 31.89 -- 3.30E+12 2109594 6461 MWEDDINGTON



API04 Repeat Sequence












Page 47

Table 16. Fuel Sulfur Reversibility Study Dataset for Analysis, API05 and API06

Step

Test Start Date

Control Number Fuel

WTD Bag THC GPM

WTD Bag CH4 GPM

WTD Bag

NMHC GPM

WTD Bag

NMOG GPM

WTD Bag NOx GPM

WTD Bag

NMOG +NOx GPM

WTD Bag CO

GPM

WTD Bag CO2 GPM

WTD Bag

ECON MPG

WTD MSS Soot

(mg/mi)

WTD CPC


Test Number

Odo- meter Driver

Test 0 3/21/2013 API05 PRLEV3_10 0.0151 0.0051 0.0102 0.0113 0.0126 0.0239 0.4261 312.62 27.21 1.137 3.73E+12 2110059 9803 MWEDDINGTON





















Page 48

8.0 Sulfur Reversibility Study Results - Statistical Analysis

8.1 Statistical Analysis Approach

A statistical analysis was performed to determine if the exhaust emissions effects caused by exposure to 80 ppm sulfur fuel were reversible, after the vehicle was refueled with 10 ppm sulfur fuel.

Independent variables included the vehicle model and state. The state is defined as tests performed either before or after the 80 ppm sulfur fuel exposure. The analysis approach allowed conclusions to be drawn for individual vehicles, and for the combined test fleet of six vehicles. Dependent variables (or responses) included NMOG, NOx, CO, soot and PN. Weighted certification-quality bag emissions were the measure of most importance, and used for the statistical analysis due to the implication of fuel sulfur content on proposed EPA Tier 3 regulatory requirements.

There were nominally ten data points for each reversibility sequence run: four baseline tests run on 10 ppm sulfur fuel, three tests using 80 ppm fuel, and three tests after the vehicle was switched back to 10 ppm fuel (Section 3 and 7). Mean emissions were calculated for the baseline tests run on 10 ppm sulfur fuel,

. Mean emissions were also calculated for the reversibility tests run after the vehicle was switched back to 10 ppm fuel,

. Confidence intervals were estimated for the difference of the means,

. If the confidence interval for the difference in mean emissions included zero, then mean emissions before and after exposure to the 80 ppm fuel were not statistically different and the hypothesis that the sulfur effects on emissions were irreversible would be rejected.

The statistical analysis followed the approach used for a previous CRC sulfur effects reversibility study [Ref. 4]. This analysis approach has also been documented and applied for small sample sizes in the medical field [Ref. 18]. The equations from the latter reference were used to independently confirm the correct application of the analysis method to the present study.

To assess the validity of common statistics assumptions, the data was checked for normality using the Kolmogorov–Smirnov test. There was no basis to reject normality for HC, CH4 and CO emissions. However, normality was rejected for NOx, soot and PN emissions (p-value≤0.05, Figure 24). When the sample size is small as in this study, the mean and standard deviations may be skewed by extreme data values present in non-normal distributions. Consistent with previously published vehicle exhaust emissions studies, natural log transformed emissions more closely adhered to normality assumptions and were used for the statistical analysis. Natural log transformations were performed for all dependent variables (or responses) of interest, including NMOG, NOx, CO, soot and PN.

For the following equations, the symbol and subscript designates natural log transformed values, and the symbol and subscript represents values in the raw system of measure. In this context, the values of correspond to bag emissions expressed in measured units and are not to be confused with raw exhaust stream measurements. The index corresponds to the baseline emissions data, and corresponds to the reversibility emissions data using 10 ppm fuel, taken after the exposure to 80 ppm fuel. Subsequently, the index is referred to as the state.


Page 49

Figure 24. Data Distributions for NOx and Soot Emissions

From the measured emissions data designated

Eq. 1

Using this natural log transformed data, the transformed mean and transformed standard deviation were calculated for each vehicle. In the raw system, the mean and standard deviation were

determined as

Eq. 2

(

) ( )

Eq. 3

√( (

) ) ( ) ( )

The difference in the means between the two states was

Eq. 4

The standard error used for confidence interval calculation around was

Eq. 5

( ) √ (

) (

)

where from Taylor series approximation and the number of samples for the state, ,


Page 50

Eq. 6

( )

(

) (

) ( )

The 95% confidence intervals were then calculated for each vehicle using the Student-t distribution. Degrees of freedom were estimated using the Satterthwaite formula.

Eq. 7

(

)

The data for all six vehicles were pooled together in order to make conclusions about reversibility for the test fleet. The approach for pooling the data was also taken from [Ref. 18].

The pooled standard deviation in the log transformed system was calculated by

Eq. 8

√( )

( ) ( )

where the index represented the number of groups being pooled, or for the number of vehicles times two states being pooled. The pooled mean for each state, , was calculated by

averaging from the six vehicles. The standard error used for pooled calculations was

Eq. 9

( ) √ (

) (

( )

( )

( ( ) ( ))

( ))

The pooled values for , , and ( ) were then inputs for equations 2, 3, 4 and 7 to determine

the difference of means and confidence intervals for the fleet of vehicles tested. Confidence intervals pertaining to the fleet difference of means were much narrower due to the better estimates of pooled standard errors, and because of the greatly increased degrees of freedom for the t statistics.

One key difference between the present study and the CRC reversibility study [Ref. 4] was the number of tests used for comparing reversibility. In the CRC study, eight tests were run before and six tests were run after the high sulfur fuel exposure. In contrast, four tests were run before and three tests were run after the 80 ppm fuel exposure in the present study. Therefore, the criteria for reversibility may be considered more stringent for the present study because only half the time was allowed for emissions stabilization.


Page 51

8.2 Statistical Analysis Results and Discussion

The reversibility of the sulfur effects was evaluated by comparing emissions before and after the exposure to 80 ppm fuel. Tests before and after the exposure were run using 10 ppm sulfur fuel. The mean emissions after the exposure were subtracted from the mean baseline emissions before the exposure and 95% confidence intervals were calculated for the difference of the means per Section 8.1. The difference in the means is shown in Figure 25. A negative mean difference result indicated the mean emissions were higher after the 80 ppm fuel exposure. If the confidence interval included zero, then mean emissions before and after exposure to the 80 ppm fuel were not statistically different and the hypothesis that the sulfur effects on emissions were irreversible would be rejected. If the hypothesis was rejected, the emissions were considered to be reversible.

NMOG, NOx, and CO were reversible for all vehicles in the study following the 80 ppm fuel exposure. Some of the confidence intervals were quite large for individual vehicle, reflecting the variation in emissions from Figures 11-16. Confidence intervals for fleet means were much narrower due to the better estimates of pooled standard errors, and because of the greatly increased degrees of freedom for the t statistics.

Soot and PN emissions were reversible for the fleet, and also for five of the six vehicles. Soot and PN emissions were not reversible for the initial sequence tests for vehicle API04, as the mean was negative and the confidence interval did not include zero (Figure 25). The data from Figure 14 illustrate higher soot and PN emissions following the 80 ppm fuel exposure (Figure 14 “Initial Sequence”). The soot and PN emissions results were further explored for vehicle API04.

The soot and particle number measurements are completely independent of each other (Section 6.2). Soot and PN results for all FTP75 emissions tests performed for vehicle API04 are shown on Figure 26. A strong linear correlation existed between soot mass and PN emissions, as expected since both instruments measured elemental carbon and excluded volatile organic and sulfate aerosols. The strong soot and PN correlation (R2≥0.9) confirmed there were no measurement anomalies. The soot emissions varied widely for this GDI-equipped vehicle, ranging from 0.69 to 1.69 mg/mile over the FTP75 for 10 ppm sulfur fuel. This large range in soot emissions eclipsed the soot emissions for tests run using 80 ppm fuel, which ranged from 0.78 to 1.2 mg/mile. The test-to-test variability of the soot and PN emissions from vehicle API04 by far eclipsed the fuel sulfur effect, and indicated that the irreversibility of soot and PN emissions due to fuel sulfur (as shown in Figure 25) was a false conclusion. Putting this finding into perspective, the total PM for API04 is about 1.5/0.62 soot fraction = 2.4 mg/mile compared to a 10 mg/mile Tier 2 (and SULEV-II) standard. This finding is foreshadowing the difficulty of certifying a GDI-equipped vehicle to an EPA Tier 3/ California LEVIII PN standard of 1 to 3 mg/mile.

In order to further determine if the irreversibility of soot and PN emissions for vehicle API04 was caused by fuel sulfur, the reversibility test sequence was repeated. This dataset is referred to as the “Repeat Sequence” throughout the report. The Repeat Sequence test results for Soot and PN were substantially different than the Initial Sequence results (Figure 14), again suggesting the test-to-test variability is high for vehicle API04. The data from the Repeat Sequence was used for all subsequent statistical analysis presented in this section. The difference in mean emissions and confidence intervals are provided in Figure 27. Using the Repeat Sequence results, the hypothesis that soot and PN emissions were irreversible for vehicle API04 was rejected.


Page 52

Figure 25. Difference in Mean Emissions and 95% Confidence Intervals for 10 ppm Sulfur Fuel Before – After High Sulfur Fuel Exposure, API04 Initial Sequence Data


Page 53

Figure 26. Soot and PN Correlation for Vehicle API04, 10 ppm and 80 ppm Fuels

For individual vehicles and the vehicle fleet, NMOG, NOx, CO, Soot and PN emissions were found to be reversible following exposure to 80 ppm sulfur fuel (Figure 27). Note that some of the vehicle mean difference values were positive and negative, indicating that both small emissions increases and decreases were measured after the exposure to 80 ppm sulfur fuel. Vehicle API05 showed a soot and PN emissions decrease after 80 ppm fuel exposure and the confidence interval did not include zero indicating the difference was statistically significant. This result is likely due to the test-to-test variability in vehicle emissions and not a fuel sulfur effect, as was concluded for vehicle API04 above.

The mean values, 95% confidence intervals, standard deviation and coefficient of variation are tabulated for each state, each vehicle and for the fleet of six vehicles in Table 17. Using the same methodology described in Section 8.1, vehicle emissions using the 80 ppm fuel were compared to the mean baseline emissions using 10 ppm sulfur fuel to quantify the sensitivity to sulfur. Fleet average gaseous emissions increased when the vehicles were conditioned and tested using the 80 ppm sulfur fuel relative to the baseline tests. Fleet NMOG emissions increased by 20% (0.002 g/mile change), NOx increased by 58% (0.006 g/mile change), and CO increased by 31% (0.078 g/mile change) for 80 ppm sulfur fuel, relative to the baseline emissions using 10 ppm fuel with greater than 95% confidence. Fleet soot and PN emissions were not statistically different for 80 ppm fuel, compared to 10 ppm fuel.

Mean emissions increases for the 80 ppm fuel were conclusive for the fleet due to narrow confidence intervals resulting from pooled variances and greater degrees of freedom (Section 8.1). With a few exceptions, emissions increases for the 80 ppm fuel were not statistically conclusive for individual vehicles due to much wider confidence intervals. Four conclusions were reached with regards to individual vehicles with greater than 95% confidence:

Vehicle API02 (Civic) CO emissions increased by 54% (0.083 g/mile change) when run on 80 ppm sulfur fuel compared to baseline emissions.

Vehicle API03 (Sonata) NOx emissions increased by 74% (0.004 g/mile change) when run on 80 ppm sulfur fuel, compared to baseline emissions. Nevertheless, mean emissions of 0.009 g/mile remained well under the SULEV-II standard of 0.02 g/mile when fueled with 80 ppm fuel.

Vehicle API03 (Sonata) soot emissions increased by 11% (0.41 mg/mile change) when run on 80 ppm sulfur fuel compared to baseline emissions.

Vehicle API03 (Sonata) PN emissions increased by 17% (9.6x1011 #/mile change) when run on 80 ppm sulfur fuel compared to baseline emissions.


Page 54

Figure 27. Difference in Mean Emissions and 95% Confidence Intervals for 10 ppm Sulfur Fuel Before – After High Sulfur Fuel Exposure, API04 Repeat Sequence Data


Page 55

Table 17. Mean Emissions and 95% Confidence Intervals from Statistical Analysis

Mean 95% CI Stdev COV Mean 95% CI Stdev COV Mean 95% CI Stdev COV

NMOG (g/mile)

API01 0.0086 ± 0.0007 0.0005 0.054 0.0097 ± 0.0036 0.0014 0.148 0.0080 ± 0.0012 0.0005 0.058

API02 0.0154 ± 0.0049 0.0031 0.200 0.0171 ± 0.0034 0.0014 0.080 0.0128 ± 0.0054 0.0022 0.169

API03 0.0102 ± 0.0039 0.0024 0.239 0.0150 ± 0.0124 0.0050 0.333 0.0132 ± 0.0090 0.0036 0.276

API04 0.0078 ± 0.0027 0.0017 0.213 0.0085 ± 0.0061 0.0024 0.286 0.0063 ± 0.0019 0.0007 0.118

API05 0.0107 ± 0.0024 0.0015 0.143 0.0102 ± 0.0019 0.0008 0.074 0.0106 ± 0.0035 0.0014 0.133

API06 0.0169 ± 0.0024 0.0015 0.091 0.0258 ± 0.0274 0.0111 0.429 0.0162 ± 0.0009 0.0004 0.023

Fleet (Pooled) 0.0111 ± 0.0008 0.0019 0.170 0.0133 ± 0.0017 0.0034 0.258 0.0107 ± 0.0008 0.0016 0.152

NOx (g/mile)

API01 0.0080 ± 0.0029 0.0018 0.228 0.0169 ± 0.0090 0.0036 0.214 0.0094 ± 0.0104 0.0042 0.449

API02 0.0083 ± 0.0024 0.0015 0.185 0.0129 ± 0.0091 0.0037 0.284 0.0078 ± 0.0052 0.0021 0.270

API03 0.0051 ± 0.0004 0.0002 0.046 0.0089 ± 0.0033 0.0013 0.149 0.0063 ± 0.0014 0.0006 0.089

API04 0.0065 ± 0.0013 0.0008 0.129 0.0093 ± 0.0061 0.0025 0.264 0.0066 ± 0.0034 0.0014 0.206

API05 0.0140 ± 0.0042 0.0026 0.189 0.0248 ± 0.0336 0.0136 0.548 0.0141 ± 0.0093 0.0037 0.265

API06 0.0233 ± 0.0056 0.0035 0.151 0.0254 ± 0.0071 0.0029 0.113 0.0231 ± 0.0015 0.0006 0.027

Fleet (Pooled) 0.0095 ± 0.0007 0.0016 0.165 0.0150 ± 0.0022 0.0044 0.291 0.0100 ± 0.0013 0.0025 0.253

CO (g/mile)

API01 0.455 ± 0.451 0.286 0.629 0.436 ± 0.298 0.120 0.275 0.400 ± 0.172 0.069 0.173

API02 0.153 ± 0.058 0.036 0.238 0.236 ± 0.096 0.039 0.165 0.129 ± 0.035 0.014 0.110

API03 0.187 ± 0.039 0.025 0.132 0.232 ± 0.083 0.033 0.144 0.205 ± 0.154 0.062 0.303

API04 0.137 ± 0.030 0.019 0.136 0.234 ± 0.130 0.053 0.224 0.135 ± 0.068 0.027 0.203

API05 0.466 ± 0.052 0.033 0.070 0.509 ± 0.156 0.063 0.123 0.496 ± 0.127 0.051 0.103

API06 0.311 ± 0.029 0.018 0.059 0.456 ± 0.477 0.193 0.422 0.278 ± 0.121 0.049 0.175

Fleet (Pooled) 0.252 ± 0.029 0.069 0.273 0.330 ± 0.040 0.081 0.245 0.241 ± 0.023 0.046 0.189

Soot (mg/mile)

API01 0.38 ± 0.22 0.14 0.360 0.42 ± 0.10 0.04 0.093 0.49 ± 0.18 0.07 0.151

API02 0.27 ± 0.04 0.03 0.097 0.29 ± 0.25 0.10 0.346 0.24 ± 0.12 0.05 0.199

API03 3.65 ± 0.23 0.14 0.039 4.07 ± 0.04 0.02 0.004 3.49 ± 0.38 0.15 0.044

API04 0.83 ± 0.19 0.12 0.145 0.86 ± 0.17 0.07 0.080 0.86 ± 0.19 0.08 0.090

API05 1.21 ± 0.28 0.17 0.144 1.10 ± 0.49 0.20 0.178 0.79 ± 0.04 0.02 0.021

API06 0.12 ± 0.07 0.04 0.357 0.18 ± 0.29 0.12 0.671 0.12 ± 0.04 0.01 0.116

Fleet (Pooled) 0.60 ± 0.06 0.13 0.224 0.66 ± 0.10 0.20 0.304 0.57 ± 0.03 0.07 0.120

PN (#xE12/mile)

API01 1.01 ± 0.29 0.18 0.179 1.25 ± 0.40 0.16 0.129 1.22 ± 0.06 0.02 0.019

API02 0.65 ± 0.22 0.14 0.214 0.64 ± 0.31 0.12 0.193 0.64 ± 0.11 0.04 0.069

API03 5.68 ± 0.14 0.09 0.016 6.63 ± 0.20 0.08 0.012 5.68 ± 0.30 0.12 0.021

API04 2.61 ± 0.46 0.29 0.110 2.79 ± 0.12 0.05 0.017 2.84 ± 0.50 0.20 0.070

API05 4.16 ± 0.52 0.33 0.079 3.72 ± 1.18 0.47 0.127 2.93 ± 0.30 0.12 0.041

API06 0.29 ± 0.08 0.05 0.168 0.27 ± 0.09 0.04 0.138 0.30 ± 0.11 0.04 0.144

Fleet (Pooled) 1.51 ± 0.09 0.22 0.144 1.57 ± 0.10 0.19 0.122 1.50 ± 0.06 0.11 0.074

Baseline Tests, 10 ppm Sulfur Fuel High Sulfur Exposure, 80 ppm Sulfur Fuel Reversibility Tests, 10 ppm Sulfur Fuel


Page 56

9.0 Summary and Conclusions

Six late model vehicles were tested to determine if the exhaust emissions effects caused by exposure to 80 ppm sulfur fuel were reversible, after the vehicle was refueled with 10 ppm sulfur fuel. The reversibility test sequence included four baseline tests run on 10 ppm sulfur fuel, three high sulfur fuel exposure tests using 80 ppm fuel, and three tests after the vehicle was switched back to 10 ppm fuel.

Gaseous exhaust emissions were higher for the vehicles conditioned and tested using 80 ppm sulfur fuel, relative to baseline tests run using 10 ppm fuel. Mean emissions increased for vehicles run on the 80 ppm fuel as follows, with greater than 95% confidence:

o Fleet average NMOG increased by 20% (0.002 g/mile change) o Fleet average NOx increased by 58% (0.006 g/mile change) o Fleet average CO increased by 31% (0.078 g/mile change) o Vehicle API02 (Civic) CO emissions increased by 54% (0.083 g/mile change) o Vehicle API03 (Sonata) NOx emissions increased by 74% (0.004 g/mile change), noting

that mean emissions of 0.009 g/mile remained well under the SULEV-II standard

For the test fleet of six vehicles, average soot and PN emissions were not statistically different for 80 ppm fuel compared to 10 ppm fuel results. Only vehicle API03 (Sonata), the highest PM emitter in the study, had higher soot and PN emissions using 80 ppm fuel:

o Vehicle API03 (Sonata) soot emissions increased by 11% (0.41 mg/mile change) o Vehicle API03 (Sonata) PN emissions increased by 17% (9.6x1011 #/mile change)

A statistical analysis was performed to determine if the exhaust emissions effects caused by exposure to 80 ppm sulfur fuel were reversible, after the vehicle was refueled with 10 ppm sulfur fuel.

For each vehicle tested on 10 ppm sulfur fuel, the NMOG, NOx, CO, Soot and PN emissions were found to be reversible following exposure to 80 ppm sulfur fuel. There was greater than 95% confidence that the differences in the mean emissions values measured before and after the high sulfur fuel exposure were not statistically different.

For the fleet of six vehicles combined, the NMOG, NOx, CO, Soot and PN emissions were found to be reversible following exposure to 80 ppm sulfur fuel.

Vehicles equipped with GDI engines had about five to seven times higher soot mass and particle number emissions on average compared to the SFI-equipped vehicles.

Vehicles equipped with GDI engines had very high variability in soot and PN emissions. The vehicle emissions variability was shown to be far larger than the fuel sulfur effect under study.


Page 57

10.0 References

1. U.S. Environmental Protection Agency, “EPA Proposes Tier 3 Motor Vehicle Emission and Fuel Standards”, Office of Transportation and Air Quality EPA-420-F-13-016, March 2013.

2. Benson, J., Burns, V., Koehl, W., Gorse, R., Painter, L., Hochhauser, A., Reuter, R., "Effects of Gasoline Sulfur Level on Mass Exhaust Emissions - Auto/Oil Air Quality Improvement Research Program," SAE Technical Paper 912323, 1991.

3. Petit, A., Jeffrey, J., Palmer, F., and Steinbrink, R., "European Programme on Emissions, Fuels and

Engine Technologies (EPEFE) - Emissions from Gasoline Sulphur Study," SAE Technical Paper 961071, 1996.

4. Schleyer, C., Eng, K., Gorse, R., Gunst, R., Eckstrom, J., Freel, J., Natarajan, M., Schlenker, A.,

“Reversibility of Sulfur Effects on Emissions of California Low Emission Vehicles”, SAE Technical Paper 1999-01-1544, 1999.

5. Ball, D., Clark, D., Moser, D., “Effects of Fuel Sulfur on FTP NOx Emissions from a PZEV 4 Cylinder Application”, SAE Technical Paper 2011-01-0300, April 2011.

6. US Department of Transportation, Federal Highway Administration, “Posted Speed Limits by Functional System”, Highway Information Quarterly Newsletter, April 2002, http://www.fhwa.dot.gov/ohim/hiq/hiqapr02.htm#topicA

7. Dudek, W., “CRC Project No. E-87-1 Mid-Level Ethanol Blends Catalyst Durability Study Screening”, Transportation Research Center Inc., June 2009.

8. California Air Resources Board, “California 2015 and subsequent model criteria pollutant exhaust emission standards and test procedures and 2017 and subsequent model greenhouse gas exhaust emissions standards and test procedures for passenger cars, light-duty trucks, and medium-duty vehicles,” pp. II-3 – II-4.

9. Koehl, W., Benson, J., Burns, V., Gorse, R. et al., "Effects of Gasoline Sulfur Level on Exhaust Mass and Speciated Emissions: The Question of Linearity - Auto/Oil Air Quality Improvement Program," SAE Technical Paper 932727, 1993.

10. U.S. Environmental Protection Agency Annual Certification Test Results & Database, http://www.epa.gov/oms/crttst.htm.

11. Kubsh, J., “Advanced Emission Control Systems for Gasoline and Diesel Engines”, SAE OBD Symposium, August 2010.

12. Sims, G., Johri, S., “Catalyst Performance Study Using Taguchi Methods”, SAE Technical Paper 881589, 1988.

http://www.epa.gov/oms/crttst.htm


Page 58

13. Burkholder, S., Cooper, B., “Effect of Aging and Testing Conditions on Catalyst Performance”, SAE Technical Paper 911734, 1991.

14. California Air Resources Board, “California Evaluation Procedures for New Aftermarket Catalytic Convertors”, October 2007.

15. Sluder, S., West, B., “NMOG Emissions Characterizations and Estimation for Vehicles Using Ethanol-Blended Fuels”, Oak Ridge National Laboratory Report ORNL/TM-2011/461, October 2011.

16. West, B., Sluder, S., Knoll, K., Orban, J., Feng, J., “Intermediate Ethanol Blends Catalyst Durability Program”, Oak Ridge National Laboratory Report ORNL/TM-2011/234, February 2012.

17. Vertin, K., Glinsky, G., Reek, A., “Comparative Emissions Testing of Vehicles Aged on E0, E15 and E20 Fuels”, National Renewable Energy Laboratory Subcontractor Report NREL/SR-5400-55778, August 2012.

18. Higgins, J., White, I., Anzures-Cabrera, J., “Meta-analysis of Skewed Data: Combining Results Reported on Log-Transformed or Raw Scales”, Stat Med. 2008 December 20; 27(29): 6072–6092.


Page 59

11.0 Appendices

11.1 Fuel Sulfur Monitoring Results for Emissions Test Fuels

REGULAR OCTANE

Fuel Name Lab Sample Collection Date

ASTM

D5453

Sulfur

(ppm)

Target

Sulfur

(ppm)

Sulfur

Difference

(ppm)

CALEV3_10 Haltermann Batch 11/7/2012 9 10 -1.0

CALEV3_10 SGS-OGC Tote (Avg 5 drums) 12/19/2012 9 10 -1.0

CALEV3_10 SGS-OGC Drum 1/31/2013 8.3 10 -1.7

CALEV3_80 Haltermann Tote 11/15/2012 79 80 -1.0

CALEV3_80 SGS-OGC Drum 1 12/19/2012 81 80 1.0



PREMIUM OCTANE

Fuel Name Lab Sample Collection Date

ASTM

D5453

Sulfur

(ppm)

Target

Sulfur

(ppm)

Sulfur

Difference

(ppm)

PRLEV3_10 Haltermann Batch 10/23/2012 9 10 -1.0

PRLEV3_10 SGS-OGC Drum 1 12/19/2012 9 10 -1.0

PRLEV3_10 SGS-OGC Drum 2 1/31/2013 8.5 10 -1.5

PRLEV3_80 SGS-OGC Drum 1, Sample 1 3/19/2013 78.4 80 -1.6

PRLEV3_80 SGS-OGC Drum 1, Sample 2 3/19/2013 78.8 80 -1.2


Page 60

11.2 Certificate of Analysis for Emissions Test Fuels

Fuel ID: CALEV3_10


Page 61

Fuel ID: CALEV3_80


Page 62

Fuel ID: PRLEV3_10


Page 63


Page 64


Page 65


Page 66


Page 67


Page 68


Page 69


Page 70


Page 71


Page 72


Page 73


Page 74


Page 75


Page 76

11.3 Catalyst Aging Test Fuel Properties

Fuel Name --->ASTM

Aging Fuel

8/6/2012

Aging Fuel

9/17/2012

Aging Fuel

10/5/2012

Aging Fuel

10/11/2012

Aging Fuel

10/18/2012

Laboratory ---> Method Units Paragon Paragon Paragon Paragon Paragon

Distillation D86

IBP F 97.4 99.7 81.3

10% F 141.8 143.9 103.1

50% F 230.7 229.8 229

90% F 330.2 318.6 338.1

EP F 402.6 401.3 408.4

Sulfur D5453 ppm 18.5 43.0 30.4 34.4 31.4

RVP D5191 psi 6.6 6.7 12.53

Lead D3237 g/gal <0.001 <0.001 <0.001

Specific Gravity D4052 0.737 0.7297 0.7366 0.7356 0.7361

Carbon D5291 %mass 85.85 85.6 86.28

Hydrogen D5291 %mass 14.15 14.4 13.72

Oxygen, by calculation D4815 %mass 0 0 0

Aromatics D1319 %vol 21.7 16.7 25.6

Saturates D1319 %vol 76.6 80.4 66.9

Olefins D1319 %vol 1.7 2.9 7.5

Phosphorous D3231 g/gal <0.0002 <0.0002 <0.0002


Page 77

11.4 Exhaust and Catalyst Temperature Histograms for Aging Test

API01 Malibu Catalyst Thermal Exposure During Aging Test

0

10

20

30

40

50

60

70

80

90

100

CCC Inlet

0

10

20

30

40

50

60

70

80

90

100

Hours

at Tem

pera

ture CCC Front Bed

0

10

20

30

40

50

60

70

80

90

100

750

760

770

780

790

800

810

820

830

840

850

860

870

880

890

900

910

920

930

940

950

960

970

980

990

1000

1010

1020

1030

1040

1050

Temperature (°C)

UBC Front Bed


Page 78

API02 Civic Catalyst Thermal Exposure During Aging Test

0

10

20

30

40

50

60

70

80

90

100

0

10

20

30

40

50

60

70

80

90

100

750

760

770

780

790

800

810

820

830

840

850

860

870

880

890

900

910

920

930

940

950

960

970

980

990

1000

1010

1020

1030

1040

1050

Ho

urs

at Te

mp

era

ture

Temperature (°C)

CCC Front Bed

CCC Inlet


Page 79

API03 Sonata Catalyst Thermal Exposure During Aging Test

0

10

20

30

40

50

60

70

80

90

100

CCC Inlet

0

10

20

30

40

50

60

70

80

90

100

Hours

at Tem

pera

ture

CCC Front Bed

0

10

20

30

40

50

60

70

80

90

100

750

760

770

780

790

800

810

820

830

840

850

860

870

880

890

900

910

920

930

940

950

960

970

980

990

1000

1010

1020

1030

1040

1050

Temperature (°C)

UBC Front Bed


Page 80

API04 Focus Catalyst Thermal Exposure During Aging Test

0

10

20

30

40

50

60

70

80

90

100

CCC Inlet

0

10

20

30

40

50

60

70

80

90

100

Hours

at Tem

pera

ture

CCC Front Bed

0

10

20

30

40

50

60

70

80

90

100

750

760

770

780

790

800

810

820

830

840

850

860

870

880

890

900

910

920

930

940

950

960

970

980

990

1000

1010

1020

1030

1040

1050

Temperature (°C)

Job 6525

UBC Front Bed


Page 81

API05 A3 Catalyst Thermal Exposure During Aging Test

0

10

20

30

40

50

60

70

80

90

100

CCC Inlet

0

10

20

30

40

50

60

70

80

90

100

Ho

urs

at Te

mp

era

ture CCC Front Bed

0

10

20

30

40

50

60

70

80

90

100

750

760

770

780

790

800

810

820

830

840

850

860

870

880

890

900

910

920

930

940

950

960

970

980

990

1000

1010

1020

1030

1040

1050

Temperature (°C)

UBC Front Bed


Page 82

API06 Camry Catalyst Thermal Exposure During Aging Test


Page 83

11.5 Dynamometer Equivalent Test Weights and Road Load Coefficients

11.6 Manufacturer Recommended Motor Oils

Vehicle Model ETW (lb) A (lb) B (lb/mph) C (lb/mph2) A (lb) B (lb/mph) C (lb/mph2)

API01 Malibu 3875 35.30 0.3548 0.01960 18.41 0.0604 0.02085

API02 Civic 3125 22.65 0.2074 0.01629 9.16 0.1326 0.01589

API03 Sonata 3500 29.45 0.5673 0.01010 8.20 0.2605 0.01249

API04 Focus 3250 31.88 0.2815 0.01943 12.38 0.2474 0.01898

API05 A3 3750 32.00 0.2700 0.02000 13.09 0.2284 0.01893

API06 Camry 3750 29.52 0.1087 0.01925 14.10 -0.0855 0.02015

Target Coefficients Dyno Set Coefficients

Vehicle Viscosity Comment

2009 Chevrolet Malibu 5W-30 Synthetic oil required, to meet GM6094 spec

2012 Honda Civic EX 0W-20 This viscosity only available as a synthetic oil

2012 Hyundai Sonata 5W-20 Synthetic or conventional oil

2012 Ford Focus 5W-20 Synthetic oil required

2012 Audi A3 5W-40 Only synthetic oils currently meet VW 502 00 spec

2012 Toyota Camry 0W-20 This viscosity only available as a synthetic oil

Mobil 1 Synthetic Oil was used for all test vehicles


Page 84

11.7 Catalyst Warm-Up and NOx Light-Off for Each Vehicle, Reversibility Sequence, FTP75

Vehicle API01 - Malibu


Page 85

Vehicle API02 - Civic


Page 86

Vehicle API03 - Sonata


Page 87

Vehicle API04 – Focus – Repeat Sequence


Page 88

Vehicle API05 – A3


Page 89

Vehicle API06 – Camry


Page 90

11.8 Raw Exhaust Emissions and Catalyst Conversion Efficiency


Page 91

Vehicle API01 - Malibu

■ 10ppm Sulfur Fuel (Baseline) ■ 80ppm Sulfur Fuel ■ 10ppm Sulfur Fuel (Reversibility)


Page 92

Vehicle API02 - Civic



Page 93

Vehicle API03 - Sonata



Page 94

Vehicle API04 – Focus – Initial Sequence



Page 95

Vehicle API04 – Focus – Repeat Sequence



Page 96

Vehicle API05 – A3



Page 97

Vehicle API06 - Camry



Page 98

11.9 Soot, Particle Number and Size Distribution Reports


Page 99

Particle Number and Particle Size Distribution Report - FTP75 Drive Cycle


Driver:

Fuel:

MWEDDINGTON

CALEV3_10

Driver: MWEDDINGTON

Fuel: CALEV3_10

1/30/2013 11:38

Phase II

2.18E+10

4.59E+11

0.034

3.85

Phase I

4.67E+12

5.55E+12

1.442

3.61

CPC Max Raw Particle Concentration (#/cc)

CPC Max Corrected Particle concentration (#/cc)

TestID: 2109191

CarID: API01

Date: 1/30/2013 11:38

-

-

-

-

-

5.04E+02

344.92

1.69E+13

2.01E+13

5.21

50.84

Phase I

1.30E+04

6.58E+06

Temp of Evaporator Tube Avg (deg C)

5.82

Weighted

1.02E+12

1.54E+12

0.333

-

300.00

Phase III

1.13E+11

5.44E+11

0.057

3.59

Phase II

5.32E+01

2.68E+04

70.09

5.99

5.04E+02

6.20

8.40E+10

1.77E+12

0.13

-

TestID:

CarID:

Date:

2109191

API01

344.58

1.00

154.31

300.00

Phase III

5.70E+02

2.87E+05

70.09

5.99

5.04E+02

5.77

4.07E+11

1.95E+12

0.21

-

344.84

1.00

154.27

1.00

154.27

300.00

70.09

6.00

Results Summary

CPC Particle Number (#/mi)

EEPS Particle Number (#/mi)

MSS Soot Mass (mg/mi)

Distance (mi)

CVS Flow Avg (scfm)

MSS Dilution Ratio Avg

Temp of Rotating Disk Diluter Avg (deg C)

TSI First Stage Dilution Factor Avg

TSI Second Stage Dilution Factor Avg

TSI Correction Factor Avg

Distance (km)

CPC Particle Number (#)

EEPS Particle Number (#)

MSS Soot Mass (mg)

Median Particle Dia at Peak Emission (nm)

0

5000

10000

15000

20000

25000

30000

35000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]

Particle Diameter (nm)

Particle Size Distribution at Peak Emission Rate

0

10

20

30

40

50

60

70

0

2E+11

4E+11

6E+11

8E+11

1E+12

1.2E+12

1.4E+12

1.6E+12

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)

Instantaneous Particle Number over FTP75 Phase I

EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

70

0

0.5

1

1.5

2

2.5

3

3.5

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)

Soot Concentration over FTP75 Phase I

MSS_CC (mg/m3)

Speed (mph)


Page 100



Driver:

Fuel:

MWEDDINGTON

CALEV3_80

Driver: MWEDDINGTON

Fuel: CALEV3_80

2/5/2013 10:14

Phase II

3.67E+10

3.59E+11

0.072

3.88

Phase I

5.39E+12

6.38E+12

1.574

3.61



TestID: 2109309

CarID: API01

Date: 2/5/2013 10:14

-

-

-

-

-

5.04E+02

347.12

1.94E+13

2.30E+13

5.67

52.34

Phase I

1.49E+04

7.51E+06


5.80

Weighted

1.18E+12

1.60E+12

0.391

-

300.00

Phase III

1.67E+11

3.35E+11

0.099

3.60

Phase II

1.47E+02

7.42E+04

70.10

6.00

5.04E+02

6.25

1.43E+11

1.39E+12

0.28

-

TestID:

CarID:

Date:

2109309

API01

346.84

1.00

154.25

300.00

Phase III

6.49E+02

3.27E+05

70.10

5.99

5.04E+02

5.79

5.99E+11

1.21E+12

0.36

-

347.13

1.00

154.22

1.00

154.22

300.00

70.10

6.00

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

5000

10000

15000

20000

25000

30000

35000

40000

45000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

0

2E+11

4E+11

6E+11

8E+11

1E+12

1.2E+12

1.4E+12

1.6E+12

1.8E+12

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)


Page 101



Driver:

Fuel:

MWEDDINGTON

CALEV3_10

Driver: MWEDDINGTON

Fuel: CALEV3_10

1/31/2013 12:25

Phase II

3.43E+10

4.10E+11

0.036

3.86

Phase I

3.18E+12

3.71E+12

1.010

3.62



TestID: 2109229

CarID: API02

Date: 1/31/2013 12:25

-

-

-

-

-

5.04E+02

347.99

1.15E+13

1.34E+13

3.66

55.36

Phase I

7.71E+03

3.89E+06


5.82

Weighted

6.97E+11

1.16E+12

0.237

-

300.00

Phase III

6.22E+10

6.28E+11

0.029

3.59

Phase II

2.93E+01

1.48E+04

70.10

5.99

5.04E+02

6.21

1.32E+11

1.58E+12

0.14

-

TestID:

CarID:

Date:

2109229

API02

347.81

1.00

154.18

300.00

Phase III

6.55E+01

3.30E+04

70.10

5.99

5.04E+02

5.78

2.24E+11

2.26E+12

0.10

-

348.30

1.00

154.13

1.00

154.12

300.00

70.10

6.00

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

5000

10000

15000

20000

25000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

70

0

1E+11

2E+11

3E+11

4E+11

5E+11

6E+11

7E+11

8E+11

9E+11

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

70

0

0.5

1

1.5

2

2.5

3

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)


Page 102



Driver:

Fuel:

MWEDDINGTON

CALEV3_80

Driver: MWEDDINGTON

Fuel: CALEV3_80

2/6/2013 9:09

Phase II

1.12E+11

9.54E+11

0.052

3.87

Phase I

3.33E+12

4.52E+12

1.266

3.61



TestID: 2109346

CarID: API02

Date: 2/6/2013 9:09

-

-

-

-

-

5.04E+02

345.40

1.20E+13

1.63E+13

4.57

54.90

Phase I

6.55E+03

3.30E+06


5.81

Weighted

7.75E+11

1.59E+12

0.300

-

300.00

Phase III

9.79E+10

5.60E+11

0.036

3.59

Phase II

1.41E+03

7.13E+05

70.09

5.99

5.04E+02

6.23

4.32E+11

3.69E+12

0.20

-

TestID:

CarID:

Date:

2109346

API02

345.37

1.00

154.31

300.00

Phase III

8.76E+02

4.42E+05

70.09

6.00

5.04E+02

5.79

3.52E+11

2.01E+12

0.13

-

345.76

1.00

154.29

1.00

154.31

300.00

70.09

6.00

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

0

1E+11

2E+11

3E+11

4E+11

5E+11

6E+11

7E+11

8E+11

9E+11

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

0

0.5

1

1.5

2

2.5

3

3.5

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)


Page 103



Driver:

Fuel:

MWEDDINGTON

CALEV3_10

Driver: MWEDDINGTON

Fuel: CALEV3_10

2/7/2013 13:20

Phase II

2.97E+12

2.20E+12

1.369

3.87

Phase I

1.81E+13

2.27E+13

12.770

3.60



TestID: 2109383

CarID: API03

Date: 2/7/2013 13:20

-

-

-

-

-

5.04E+02

348.37

6.52E+13

8.17E+13

45.93

70.94

Phase I

1.36E+04

6.88E+06


5.79

Weighted

5.64E+12

6.00E+12

3.471

-

300.00

Phase III

1.24E+12

5.84E+11

0.423

3.58

Phase II

2.00E+03

1.01E+06

70.09

6.00

5.04E+02

6.23

1.15E+13

8.50E+12

5.30

-

TestID:

CarID:

Date:

2109383

API03

348.03

1.00

154.15

300.00

Phase III

8.01E+02

4.03E+05

70.09

5.99

5.04E+02

5.76

4.42E+12

2.09E+12

1.51

-

348.62

1.00

154.14

1.00

154.13

300.00

70.09

6.00

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

10000

20000

30000

40000

50000

60000

70000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

0

5E+11

1E+12

1.5E+12

2E+12

2.5E+12

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

0

2

4

6

8

10

12

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)


Page 104



Driver:

Fuel:

MWEDDINGTON

CALEV3_80

Driver: MWEDDINGTON

Fuel: CALEV3_80

2/14/2013 8:31

Phase II

4.02E+12

3.49E+12

1.973

3.91

Phase I

1.91E+13

2.53E+13

13.731

3.62



TestID: 2109500

CarID: API03

Date: 2/14/2013 8:31

-

-

-

-

-

5.04E+02

346.99

6.92E+13

9.15E+13

49.71

72.11

Phase I

1.46E+04

7.34E+06


5.83

Weighted

6.57E+12

7.49E+12

4.066

-

300.00

Phase III

1.92E+12

1.63E+12

0.738

3.60

Phase II

2.12E+03

1.07E+06

70.09

6.00

5.04E+02

6.30

1.57E+13

1.37E+13

7.72

-

TestID:

CarID:

Date:

2109500

API03

346.68

1.00

154.08

300.00

Phase III

1.14E+03

5.74E+05

70.09

6.00

5.04E+02

5.79

6.89E+12

5.85E+12

2.65

-

346.71

1.00

154.06

1.00

154.04

300.00

70.09

6.00

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

10000

20000

30000

40000

50000

60000

70000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

0

5E+11

1E+12

1.5E+12

2E+12

2.5E+12

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

0

2

4

6

8

10

12

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)


Page 105



Driver:

Fuel:

MWEDDINGTON

CALEV3_10

Driver: MWEDDINGTON

Fuel: CALEV3_10

5/13/2013 12:34

Phase II

1.51E+12

1.69E+12

0.435

3.85

Phase I

6.79E+12

7.51E+12

2.317

3.58



TestID: 2110638

CarID: API04

Date: 5/13/2013 12:34

-

-

-

-

-

5.04E+02

347.51

2.43E+13

2.69E+13

8.29

44.91

Phase I

4.64E+03

2.34E+06


5.76

Weighted

2.85E+12

3.07E+12

0.887

-

300.00

Phase III

2.42E+12

2.31E+12

0.660

3.60

Phase II

1.03E+03

5.21E+05

70.09

5.99

5.04E+02

6.20

5.80E+12

6.52E+12

1.67

-

TestID:

CarID:

Date:

2110638

API04

347.11

1.00

154.16

300.00

Phase III

2.25E+03

1.14E+06

70.10

5.99

5.04E+02

5.79

8.72E+12

8.32E+12

2.38

-

347.46

1.00

154.13

1.00

154.12

300.00

70.09

5.99

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

2000

4000

6000

8000

10000

12000

14000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

70

0

5E+10

1E+11

1.5E+11

2E+11

2.5E+11

3E+11

3.5E+11

4E+11

4.5E+11

5E+11

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

70

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)


Page 106



Driver:

Fuel:

MWEDDINGTON

CALEV3_80

Driver: MWEDDINGTON

Fuel: CALEV3_80

5/16/2013 11:59

Phase II

1.55E+12

5.41E+12

0.407

3.79

Phase I

6.63E+12

1.10E+13

1.995

3.58



TestID: 2110675

CarID: API04

Date: 5/16/2013 11:59

-

-

-

-

-

5.04E+02

344.11

2.37E+13

3.93E+13

7.14

51.15

Phase I

5.41E+03

2.73E+06


5.76

Weighted

2.84E+12

6.06E+12

0.783

-

300.00

Phase III

2.36E+12

3.54E+12

0.568

3.56

Phase II

7.96E+02

4.01E+05

70.09

5.99

5.04E+02

6.11

5.89E+12

2.05E+13

1.54

-

TestID:

CarID:

Date:

2110675

API04

343.76

1.00

154.15

300.00

Phase III

1.98E+03

9.97E+05

70.09

6.00

5.04E+02

5.73

8.40E+12

1.26E+13

2.02

-

344.11

1.00

154.14

1.00

154.12

300.00

70.09

5.99

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

2000

4000

6000

8000

10000

12000

14000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

0

1E+11

2E+11

3E+11

4E+11

5E+11

6E+11

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)


Page 107



Driver:

Fuel:

MWEDDINGTON

PRLEV3_10

Driver: MWEDDINGTON

Fuel: PRLEV3_10

3/27/2013 7:27

Phase II

2.85E+12

5.07E+12

0.702

3.86

Phase I

6.90E+12

9.92E+12

1.720

3.59



TestID: 2110113

CarID: API05

Date: 3/27/2013 7:27

-

-

-

-

-

5.04E+02

346.92

2.48E+13

3.56E+13

6.18

52.05

Phase I

8.55E+03

4.34E+06


5.78

Weighted

4.34E+12

6.30E+12

1.277

-

300.00

Phase III

5.20E+12

5.91E+12

2.026

3.59

Phase II

3.69E+03

1.86E+06

70.09

5.99

5.04E+02

6.21

1.10E+13

1.96E+13

2.71

-

TestID:

CarID:

Date:

2110113

API05

346.70

1.00

154.16

300.00

Phase III

8.21E+03

4.14E+06

70.09

5.99

5.04E+02

5.78

1.87E+13

2.12E+13

7.28

-

346.91

1.00

154.11

1.00

154.14

300.00

70.09

6.00

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

5000

10000

15000

20000

25000

30000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

70

0

2E+11

4E+11

6E+11

8E+11

1E+12

1.2E+12

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

70

0

0.5

1

1.5

2

2.5

3

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)


Page 108



Driver:

Fuel:

MWEDDINGTON

PRLEV3_80

Driver: MWEDDINGTON

Fuel: PRLEV3_80

4/1/2013 12:59

Phase II

2.51E+12

2.76E+12

0.623

3.86

Phase I

8.70E+12

1.14E+13

2.798

3.59



TestID: 2110152

CarID: API05

Date: 4/1/2013 12:59

-

-

-

-

-

5.04E+02

346.92

3.12E+13

4.08E+13

10.04

56.13

Phase I

1.64E+04

8.29E+06


5.77

Weighted

4.24E+12

5.11E+12

1.306

-

300.00

Phase III

4.16E+12

4.83E+12

1.469

3.58

Phase II

2.81E+03

1.42E+06

70.09

5.99

5.04E+02

6.21

9.68E+12

1.07E+13

2.40

-

TestID:

CarID:

Date:

2110152

API05

346.63

1.00

154.18

300.00

Phase III

5.02E+03

2.53E+06

70.09

5.99

5.04E+02

5.76

1.49E+13

1.73E+13

5.26

-

347.18

1.00

154.13

1.00

154.13

300.00

70.09

6.00

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

10000

20000

30000

40000

50000

60000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

70

0

5E+11

1E+12

1.5E+12

2E+12

2.5E+12

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

70

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)


Page 109



Driver:

Fuel:

MWEDDINGTON

CALEV3_10

Driver: MWEDDINGTON

Fuel: CALEV3_10

2/13/2013 9:54

Phase II

4.43E+10

6.97E+11

0.096

3.84

Phase I

1.04E+12

1.35E+12

0.255

3.60



TestID: 2109476

CarID: API06

Date: 2/13/2013 9:54

-

-

-

-

-

5.04E+02

344.85

3.76E+12

4.86E+12

0.92

37.06

Phase I

3.24E+03

1.63E+06


5.79

Weighted

2.55E+11

7.04E+11

0.120

-

300.00

Phase III

5.40E+10

2.29E+11

0.063

3.58

Phase II

2.01E+01

1.01E+04

70.09

5.99

5.04E+02

6.17

1.70E+11

2.67E+12

0.37

-

TestID:

CarID:

Date:

2109476

API06

345.23

1.00

154.09

300.00

Phase III

2.47E+02

1.25E+05

70.09

5.99

5.04E+02

5.77

1.93E+11

8.19E+11

0.23

-

345.07

1.00

154.03

1.00

154.06

300.00

70.09

5.99

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

0

5E+10

1E+11

1.5E+11

2E+11

2.5E+11

3E+11

3.5E+11

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)


Page 110



Driver:

Fuel:

MWEDDINGTON

CALEV3_80

Driver: MWEDDINGTON

Fuel: CALEV3_80

2/19/2013 8:07

Phase II

1.63E+10

5.84E+11

0.047

3.87

Phase I

1.00E+12

1.77E+12

0.211

3.60



TestID: 2109556

CarID: API06

Date: 2/19/2013 8:07

-

-

-

-

-

5.04E+02

349.13

3.60E+12

6.36E+12

0.76

43.99

Phase I

2.57E+03

1.30E+06


5.79

Weighted

2.33E+11

7.39E+11

0.079

-

300.00

Phase III

6.17E+10

2.56E+11

0.038

3.60

Phase II

1.62E+01

8.15E+03

70.09

6.00

5.04E+02

6.24

6.32E+10

2.26E+12

0.18

-

TestID:

CarID:

Date:

2109556

API06

348.93

1.00

154.13

300.00

Phase III

6.02E+02

3.04E+05

70.09

6.00

5.04E+02

5.79

2.22E+11

9.19E+11

0.14

-

349.23

1.00

154.10

1.00

154.14

300.00

70.09

6.00

Results Summary




Distance (mi)

CVS Flow Avg (scfm)






Distance (km)



MSS Soot Mass (mg)


0

1000

2000

3000

4000

5000

6000

7000

10 100

Raw

Co

nce

ntr

atio

n [

dN

/dlo

gDp

, #/c

c]



0

10

20

30

40

50

60

0

5E+10

1E+11

1.5E+11

2E+11

2.5E+11

3E+11

0 100 200 300 400 500

Spee

d (

mp

h)

Par

ticl

e N

um

ber

Time (s)


EEPS_PN (#)

CPC_PN (#)

Speed (mph)

0

10

20

30

40

50

60

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 100 200 300 400 500

Spee

d (

mp

h)

Soo

t C

on

cen

trat

ion

(m

g/m

3)

Time (s)


MSS_CC (mg/m3)

Speed (mph)

REVERSIBILITY OF GASOLINE SULFUR EFFECTS … › downloads › api-report-sulfur...The impact of...

Documents

Transcript of REVERSIBILITY OF GASOLINE SULFUR EFFECTS … › downloads › api-report-sulfur...The impact of...