In spite of stable emission standards in force since 1981, automotive emission control technology has contined to evolve at a very rapid pace. In this paper, a very detailed forecast of emission controls for U.S. fleet of new cars is described. Forecasts of emission control technology mix by every combination of fuel system/catalyst system/secondary air system/EGR system are derived. Data on the fleet mix of emission controls is presented for the 1982-1990 time frame.Each of these different types of systems have different failure modes that lead to significantly different malperformance model emissions. Using data derived from emissions tests of vehicles that were intentionally disabled, estimates of the emissions from malperforming vehicles of the future are drawn. The estimates may form the basis of in-use emissions forecasts in the future.