Development of Chassis-Based Inspection and Maintenance Program for Heavy-Duty Diesel Vehicles

1. California Environmental Protection Agency Air Resources Board 13th CRC On-Road Vehicle Emissions Workshop San Diego, California April 2003 Presented by: Donald J. Chernich dchernic@arb.ca.gov DEVELOPMENT OF A CHASSIS BASED INSPECTION AND MAINTENANCE PROGRAM FOR HEAVY-DUTY DIESEL POWERED VEHICLES

2. SIP Commitment/M17 Project Goals Emission Reductions - TPD in SCAB (Southern CA) As a result of environmental law suit, the timeline for M17 was accelerated by 1 year.

3. Elements of SIP Measure M17 • Emission reductions from in-use HDDEs • 10 TPD NOx, 1 TPD ROG in SCAB 2010 • Strategies to be considered • HDDE NOx field screening program • HDDE in-use compliance test program • Heavy-duty on-board diagnostic program

4. Development of a Field NOx Screening Test • How Would the Program Work? • Portable dynamometers set up at roadside locations • Enroute heavy-duty trucks would be detached from trailers • Emissions testing for excess NOx conducted • Repairs required for failing trucks

5. Truck ready for testing. Laboratory grade emissions analyzers. Clean lab ready for next truck. ARB staff performing power curve test. Stockton Laboratory

6. Powercurve Test Cycle Analysis Region 100 hp line Ramp Lugdown

7. Test Sequence Comparison • Emission results • Calculated g/whp-hr, g/mi, g/gal • Modal comparison between 3 test sequence • QA for Modal CO, CO2, THC, and NOx • Integrated Modal emission rate • QA for integrated MPG, CO, CO2

8. I/M Test Cycle Evaluation Criteria • NOx calculated in (grams/wheel hp-hour) for pre- and post-repair tests (mechanical repairs only) • g/whp-hr is a uniform matrix treats low and high hp engines equally and demonstrates repeatability within and between tests • Vehicles were sent for repairs if the pre-repair NOx g/whp-hr >8 (more repair data needed) • The test must be repeatable for a broad range of vehicles. • Cycle duration need only be as long as necessary to get a representative emission rate

9. Vehicle Testing Summary • 91 vehicles tested • Selection designed to characterize HDD Vehicle Fleet • 1550 total tests conducted • 42 vehicles sent for repair

10. Critical Questions to Determine Value of Program 1. Are there excess NOx emissions in the vehicle population that are caused by tampering & malmaintenance? 2. Is there a practical field test that can identify those vehicles with high NOx emissions? 3. Can these excess NOx emissions be reduced through repairs and maintenance? 4. Can the reduction be made cost-effectively?

11. What Percentage of HDD Population can be Characterized as High NOx Emitters? • 15 percent may have excess NOx • Highest emitter group constitutes 5% of the population, >12 g/whp-hr. • No clear line between high and normal emitters Percentiles Plot 14 12 10 Mean NOx (gwhp_hr) 8 6 4 2 0 20 40 60 80 100 Percentile

12. Effect of Repairs on NOx Emissions (g/whp-hr) 16 14 12 10 (1) Pre-repair NOx (g/whp-hr) Pre and Post (2) Post-repair 8 6 4 2 0284 1388 1429 3622 3990 4635 5756 6401 7419 8165 8592 9707 0529 0757 3664 3994 5594 6184 7182 8866 9051 VEH_SER_NO Mechanical Repairs Only N = 21 Reflashes not included

13. Effects of Repairs(10g/whp-hr cutpoint) • 3 trucks showed emissions decrease • 2 trucks showed emissions increase • 1 truck unchanged • Average reduction / per truck repaired: • 2.1% • Approx. 3TPD reduction in South Coast • Average Repair cost: $1018

14. NOx Screening Program Conclusions • Current data indicates difficulty in developing a NOx screening test • Per vehicle emission reductions from repair are minimal • No clear cut point to screen out high emitters • ARB will continue to investigate magnitude and causes of high NOx emissions from HDD vehicles

15. Changing NOx with Time During Three Steady State Modes(NOx vs. Vehicle Power)

16. 14 12 10 Mfr 1 Mfr 2 8 NOx g/whp-hr Mfr 3 Mfr 4 6 Mfr 5 4 2 0 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 Model Year Baseline NOx Test Resultsby Model Year 6 g Std. 5 g Std. 4 g Std. NOx Standard (g/bhp-hr)

17. UDDS Test Data NOx vs. Model Year

18. UDDS Test DataPM vs. Model Year

20. Proof of ConceptLarge Scale HD I/M Program with Portable Analyzer • Concept: • Use existing repair grade dynamometers and portable emissions analyzers. • An extensive network of waterbrake dynamometers exists in the state. • Simultaneous measurements with a Sensor’s SEMTECH-D emissions analyzer were collected. • CARB and SEMTECH Mass emissions computed using intake airflow meter and dyno power.

21. CO2 NOx CO THC Concentration Range (mean flow weighted) 6.1 – 7.8% 481 – 1385 ppm 25 – 93 ppm 17 – 103 ppmC Mass Emissions Range g/whp-hr 520 – 700 4.4 – 11.3 0.1 – 0.5 0.04 – 0.3 Emissions Standard g/Bhp-hr NA 4 – 6 15.5 1.3 95% CI Measurement Uncertainty, g/whp-hr 12.8 0.23 0.12 0.036 Coefficient of Variance, % of standard 2.1% @ 610 g/whp-hr 4.6% @ 5 g/whp-hr 0.7% @ 15 g/whp-hr 2.8% @ 1.3 g/whp-hr SEMTECH-D Correlation Results

22. SEMTECH-D Correlation Results(Continued) • SEMTECH-D Correlation results consistent with published data. • Coefficient of Variance was less than 5% for all pollutants at applicable standards. • Exceeds EMA Task Force standards of 10%. • SEMTECH-D accuracy is suitable for a large scale I/M program.

23. NOx Screening Program Conclusions • Large scale I/M program with existing dynamometers and portable emissions analyzers is feasible from a technical standpoint. • Current data indicates difficulty in developing an effective NOx screening test. • Per vehicle emission reductions from repair are minimal. • There may be other unidentified engine problems that repairs did not address. • No clear cut point to screen out high emitters. • ARB will continue to investigate magnitude and causes of high NOx emissions from HDD vehicles.

24. Acknowledgements It is with sincere gratitude that I would like to thank all the people who helped with the development of the Stockton Laboratory and with the M17 testing effort: Mark Burnitzki, Robert Ianni, Tullie Flower, Mike Bernard, Roelof Riemersma, Brian Weitz, John Urkov, Allen Lyons, MSOD QA Section, Dipak Bishnu, Tom Cackette, Kathleen Walsh, Jim Ryden, Paul Jacobs, Chuck Owens, William Vance, Hector Maldonaldo Yvette Friend, Anise Foust, Arlene Bingaman, Lynn Pile, and Paul Loscutoff. Special Thanks to: Bell Turbo of Stockton (Barbara, Pius, Bill and Joe) DynoMaster (Rob and Lynette Youngblood) UC Riverside CE-CERT (Dr. Wayne Miller, Matt Smith, and Ted Younglove) Sensors, Inc. (Carl Ensfield, Atule Shaw, and Rob Wilson) California Analytical Inc. (Loren Mathews and Matt Swanson) Sincerely, Don Chernich The Statements and Conclusions presented are not necessarily those of the California Air Resources Board . The mention of commercial products reported herein is not to be construed as an actual or implied endorsement of such products.