FUEL-ECONOMY AND MOTOR-VEHICLE EMISSIONS

The conventional wisdom is that there is no relationship between fuel economy and motor vehicle emissions, at least for new cars. The requir ement that all vehicles meet a common emission standard in terms of gr ams per mile effectively breaks whatever link there might have been be tween fuel economy and emissions in uncontrolled (preregulatory) vehic les. As cars age, however, the emission control equipment tends to bre ak down, providing reason to think that the conventional wisdom might do the same. This paper reports on an empirical examination of this pr oposition, by linking EPA fuel economy certification data to a large d atabase of motor vehicle emission measurements collected by remote sen sing. It is found that better fuel economy is strongly associated with lower emissions of CO and HC and that the effect gets stronger as veh icles age. (C) 1997 Academic Press.