Detection of Gasoline Vehicles with Gross PM Emissions

Abstract

Light duty gasoline vehicles (LDGV) are estimated to contribute 40% of the total on-road mobile source tailpipe emissions of particulate matter (PM) in California. While considerable efforts have been made to reduce toxic diesel PM emissions going into the future, less emphasis has been placed on PM from LDGVs. The goals of this work were to characterize a small fleet of visibly smoking and high PM emitting LDGVs, to explore the potential PM-reduction benefits of Smog Check and of repairs, and to examine remote sensing devices (RSD) as a potential method for identifying high PM emitters in the in-use fleet. For this study, we recruited a fleet of eight vehicles covering a spectrum of PM emission levels. PM and criteria pollutant emissions were quantified on a dynamometer and CVS dilution tunnel system over the Unified Cycle using standard methods and real time PM instruments. The vehicles were then tested using RSD equipment over a test track, tested with a standard Smog Check, and tested with a screening device during the Smog Check. The PM emission rates of the visibly smoking vehicles range from 60 to 1718 mg/mi over the UC cycle. The light or invisible smokers had PM emissions ranging from 7 to 25 mg/mi. The smoking vehicles showed particle number rates on the order of 10