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GASOLINE/DIESEL PM SPLIT STUDY: LIGHT-DUTY VEHICLE TESTING, DATA, AND ANALYSIS
Citation:
Gabele, P A. GASOLINE/DIESEL PM SPLIT STUDY: LIGHT-DUTY VEHICLE TESTING, DATA, AND ANALYSIS. Presented at Thirteenth CRC On-Road Vehicle Emissions Workshop, San Diego, CA, April 7-9, 2003.
Impact/Purpose:
The main research question guiding this task is "how do mobile source emissions impact public health and the environment." The main objectives of this task include:
(1) Identify spatial and temporal variability in pollutant concentrations near major mobile source emission locations such as urban roadways and non-road activities.
(2) Characterize real-world emissions from on- and non-road mobile sources for use in identifying hazardous components and developing and improving mobile source emissions and human exposure models.
(3) Develop mobile source emission profiles and markers for use in human exposure and air quality receptor models.
(4) Determine the impact of emerging technologies (fuels and engine systems) on emissions and exposures to toxic pollutants.
(5) Develop and improve analytical methods that measure emissions from mobile sources.
Description:
During June 2001, the EPA participated in DOE's Gasoline/Diesel PM Split Study in Riverside, California. The purpose of the study was to determine the contribution of diesel versus gasoline-powered exhaust to the particulate matter (PM) inventory in the South Coast Air Basin. The EPA participation, which was performed under contract with CAVTC, involved recruiting (with the assistance from the California Bureau of Automotive Repair), conducting dynamometer tests, and measuring PM2.5, regulated, and gaseous air toxic emissions from 59 light-duty motor vehicles.
This presentation describes emission rates obtained for PM2.5, regulated pollutants, and gaseous air toxic compounds that were measured from the gasoline-powered test cars. Emission rates from the test vehicles are presented in context to the category in which they were recruited. Vehicles were recruited into eleven different categories based upon their age and mileage, except that one category consisted entirely of "smokers" and one of light-duty diesels. In general, emissions from the older, high mileage cars contributed the bulk of pollutant emissions from the test fleet. None of the gasoline-powered vehicles tested had a PM2.5 emission rate exceeding 200 mg/mile for the weighted, cold-start LA-92 test that was run. Therefore, it appeared that no grossly high PM emitters were recruited into this study. Comparison of emission rates derived from dilution tunnel sampling versus those from sampling in a residence chamber is made.
This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.