DATA ANALYSIS OF INDEPENDENTLY RUN EHC PROGRAMS

In the last several years, there have been a number of independently run research programs evaluating the effects of electrically-heated catalysts (EHCs) on exhaust emissions from gasoline-fueled light-duty passenger vehicles. This paper “pools” data from several of these programs to determine the fleet effect by statistical methods.

Evaluation of the overall data set from the eight car fleet indicates a very large reduction in total hydrocarbon (THC) and carbon monoxide (CO) but an accompanying increase (appreciably smaller in magnitude) in oxides of nitrogen (NOx).

A follow-up program is under way to examine fuel sensitivity issues.