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SULFATE AND PARTICULATE EMISSIONS FROM IN-USE CATALYST VEHICLES: REGULATED/UNREGULATED EMISSIONS AND FUEL ECONOMY
Citation:
Gibbs, R., G. Wotzak, S. Byer, AND N. Kolak. SULFATE AND PARTICULATE EMISSIONS FROM IN-USE CATALYST VEHICLES: REGULATED/UNREGULATED EMISSIONS AND FUEL ECONOMY. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/9-79/047 (NTIS PB82188699), 1979.
Description:
An emissions and fuel economy study of 56 catalyst cars in consumer use and maintenance has been performed by repeated testing of the cars over a two and one-half year period. This report summarizes analyses of the data base, and includes results on idle CO levels, mass emissions of HC, CO, NOx, sulfate, SO2 and total particulate; total particulate elemental analyses, catalyst activity, and fuel economy. Test cycles used were the 1975 FTP, one-hour 50 mph cruise, Congested Freeway Driving Schedule, Highway Fuel Economy Test, and idle, 30 and 50 mph cruise for catalyst activity tests. Fuel economy data for over-the-road driving are also presented from on-board totalizing fuel and engine hour meters on each car. Idle CO indicative of maladjusted carburetors (greater than 1%) was found to correlate with FTP CO emissions, purge of stored sulfur in the form of SO2 from catalysts, and decreases in catalyst activity at idle in comparison to 30(2) and 50 mph activity results. Particulate sulfur emissions accounted for only 3.7% of fuel sulfur for the 256 CFDS tests in the data base. Over-the-road fuel economy was most closely represented by the FTP (city) value.