Particulate Emission Rates from Light-Duty Vehicles in the South Coast Air Quality Management District

Abstract

This paper presents the results of a particulate emission rate study conducted on 129 light-duty gasoline and 19 light-duty diesel vehicles for the Coordinating Research Council's (CRC's) Project E-24-2. Total particulate emission rates for newer gasoline vehicles were low (<3 mg/mi) with modest increases with vehicle age and older technology. Average FTP particulate emission rates as a function of model year for gasoline vehicles were found to be 2.5 mg/mi for 1991 and newer models, 14.4 mg/mi for 1986−1990 models, 49.0 mg/mi for 1981−1985 models, and 33.8 mg/mi for 1980 and older models. High gaseous emitters were found to have approximately 5−10 times the particulate emission rates of normal emitters. The diesel vehicles had an average particulate emission rate of 561 mg/mi. It should be noted that the light-duty diesel vehicles were predominantly older, pre-1985 vehicles; the 1985 and newer diesel vehicles had substantially lower particulate emissions, i.e., less than 100 mg/mi. Emission inventory est...