Light-Duty Gasoline Vehicle High PM Emitters

This page last reviewed February 6, 2012


As PM emissions from diesel engines continue to be reduced, PM emissions from light duty gasoline vehicles (LDGV) could contribute an increasingly large fraction of remaining on-road PM emissions. While emissions from new vehicles are expected to be very low, worn or malfunctioning vehicles could have PM emissions orders of magnitude higher than normal, well-maintained vehicles.  A relatively small fraction of such vehicles could contribute a relatively large fraction of PM emissions.

The current Smog Check program in California does not include a direct measurement of PM, but will include a check for visible smoke starting in January of 2008.  The absence of PM data from Smog Checks means that we do not have a statistical distribution of PM emission data for the on-road fleet, nor an estimate for the frequency of occurrence of high PM emitters.

The objectives of this program are to:

  • Evaluate new methods for identification and possible quantification of high PM emitters, including remote sensing device (RSD) checks and quick checks feasible for use in an I/M environment.
  • Recruit at range of high PM emitting vehicles.
  • Quantify the PM emissions of the recruited vehicles.
  • Relate the PM emissions to the RSD and I/M quick check measurements.

The results of the program identified several promising tools to provide the ARB with the capability to identify high-PM emitters and to pursue cost effective emission reduction strategies. The tools are applicable in three areas: Remote Sensing Devices for PM to monitor on-road fleet traffic; tailpipe PM instruments to augment Smog Check testing; and dilution tunnel PM instruments to augment compliance testing.



  • Thomas D. Durbin et al., (2007, 2010). Light Duty Gasoline PM: Characterization of High Emitters and Valuation of Repairs for Emission Reduction. ARB Contract No. 05-323. 2007 Report (PDF - 790KB); 2010 Final Report (PDF - 735KB)

Publications for Peer-reviewed Journals

  • Wei Li et al., (2007). Detection of Gasoline Vehicles with Gross PM Emissions. SAE Technical Paper. Link

Conference Presentations

  • 18th CRC On-Road Emissions Workshop, March 31 - April 2, 2008, San Diego, CA
  • John F. Collins et al., Evaluation of High PM Emitting Light-Duty Gasoline Vehicles Using RSD, ASM, and Laboratory Dynamometer Testing. Presentation (PDF - 987KB)
  • 17th CRC On-Road Emissions Workshop, March 26-28, 2007, San Diego, CA
  • Tao Huai et al., Comparison of Remote Sensing Devices (RSD) with Gravimetric Measurements of Light-Duty Gasoline PM Emissions. Presentation (PDF - 2,011KB)
  • John F. Collins, Real-Time Measurement Methods to Detec High PM Emissions from Light-Duty Gasoline Vhicles. Presentation (PDF - 359KB)