In June 1985 the negotiations of the European Economic Community, EEC, resulted in drafts of laws providing the gradual introduction of particular exhaust emission limits for three passenger car displacement classes. The so-called EURONORM is based on previous ECE*) regulations. Fulfilment of the 1983 US standards is allowed alternatively. Outside the European Community, countries like Austria, Sweden and Switzerland have meanwhile passed their laws applying the US exhaust emission standards. The engine concepts to fulfil the different market and legal requirements range from conventional systems without catalytic converters, lean burn engines, uncontrolled catalysts to three way catalytic converter systems and diesel engines. By the forced development of low-pollution vehicles and incentive programs, the car manufacturers and the government of the Federal Republic of Germany in particular, have made important contributions to a quick reduction of passenger car exhaust emissions.