How can a gasoline or diesel vehicle be called a “clean fuel vehicle,” aren these fuels less clean than alternative fuels?
A. In general, the inherent properties of alternative fuels result in lower emissions than gasoline- or diesel-powered vehicles. But the Clean Air Act includes requirements, already in effect, that has resulted in cleaner-burning gasoline and diesel fuel, including the gasoline and diesel fuel sold in the Chicago area. These requirements have essentially narrowed the emissions gap between alternative and conventional fuels. In engineering a vehicle or engine to meet one of the CFFP standards, the manufacturer may rely more upon the cleaner-burning properties of a fuel and make few, if any, emission-related changes to the engine; make improvements to an engine’s emission control components and rely less upon the emission reductions from the properties of the fuel; or a combination of both. The goal of the CFFP is to reduce emissions. Whether these emission reductions are a result of the type of fuel, advanced vehicle emission controls, or perhaps both is entirely up to the manufacturer
