Alternative Automotive Emission Control Systems

Abstract

Relationships developed between automotive exhaust emissions and ambient air quality levels have been used to establish the degree of emission control needed to meet the ambient air quality standards in major urban areas. Interim emission standards already established for 1975 appear to be more than adequate for congested urban areas and the existing 1974 standards appear more than adequate for the remainder of the country. The very low levels mandated by the 1970 Amendments to the Clean Air Act do not appear necessary. Emission control systems based on engine modifications and thermal reactors have been shown to provide the degree of emission control needed to achieve the ambient air quality goals and are compatible with the continued use of leaded gasoline. Exhaust lead traps have been shown to be a practical means to reduce lead emissions to the environment should such control be needed. The lead tolerant control systems used with high compression ratio engines are shown to have the potential to improve fuel economy to a greater degree than proposed catalytic systems used with unleaded gasoline and low compression ratio engines. Both approaches are shown to impose severe fuel economy penalties at the very stringent emission standards mandated by the 1970 Amendments to the Clean Air Act.

A New Approach to Setting Vehicle Emission Standards

“…In general, however, the cost of the emission control hardware and fuel consumption increases with the degree of emission control imposed. 1 In view of the worsening energy supply situation in this country, it is imperative that an appropriate balance be struck between required emission levels and resulting fuel consumption penalties. It is, therefore, important to make certain that the emission standards are in fact soundly related to the air quality standards, so that we do not pay for more control than is needed to achieve the established air quality standards.…”