Characterization of Sulfate and Gaseous Emissions from California Consumer-Owned, Catalyst-Equipped Vehicles

This paper describes a study in which approximately 100 1975 and 1976 model-year, consumer-owned, catalyst-equipped vehicles in California were tested to measure the regulated exhaust gas emissions and particulate sulfate emissions. Each vehicle was tested three times over a period of approximately 11 months. All tests were conducted with the owner's brand of commercial fuel which was analyzed for sulfur and lead concentrations, Reid vapor pressure, distillation and API gravity. Emission data were analyzed to determine if there were any significant differences in sulfate and regulated gaseous emission levels between various subgroups of catalyst-equipped vehicles, and to derive average emission factors for sulfate emissions.