Particle mass emission rates from current-technology, light-duty gasoline vehicles

Now that the U.S. Environmental Protection Agency has promulgated new Natio nal Ambient Air Quality Standards for PM2.5, work will begin on generating the data required to determine the sources of ambient PM2.5 and the magnitu de of their contributions to air pollution. This paper summarizes the resul ts of an Environmental Research Consortium program, carried out under the a uspices of the U.S. Council for Automotive Research. The program focused on particulate matter (PM) emissions from representative, current-technology, light-duty gasoline vehicles produced by DaimlerChrysler Corp., Ford Motor Co., and General Motors Corp. The vehicles, for the most part taken from t he manufacturer's certification and durability fleets, were dynamometer-tes ted using the three-phase Federal Test Procedure in the companies' laborato ries. The test fleet was made up of a mixture of both low-mileage (2K-35K m iles) and high-mileage (60K-150K miles) cars, vans, sport utility vehicles, and light trucks. For each vehicle tested, PM emissions were accumulated o ver 4 cold-start tests, which were run on successive days. PM emission rate s from the entire fleet (22 vehicles total) averaged less than 2 mg/mile. A ll 18 vehicles tested using California Phase 2 reformulated gasoline had PM emission rates less than 2 mg/mile at both low and high mileages.