The Clean Air Act has imposed new standards for the maximum allowable amount of emission to escape from vehicle exhaust systems. Catalytic converters were considered as a way of satisfying the standards. The American automotive industry has decided to use platinum and palladium in the manufacture of catalytic converters for 1975 model cars. Discussed here are the results of this decision.Two effects of the converters are better fuel economy and increased use of limited material resources. This means that lighter weight cars and increased reclamation of used cars will be necessary to conserve such resources.