Projected fuel savings and emissions reductions from light-vehicle fuel economy standards

This study applies a model of motor vehicle stock turnover to estimate the effect of strengthened fuel economy standards on gasoline consumption, greenhouse gas emissions and hydrocarbon emissions by light-duty vehicles in the United States. Without significant policy change, fuel consumption is projected to grow from a 1990 level of 6.3 milliion barrels per day (Mbd) to 9Mbd by 2010. Five policy-driven scenarios are analyzed, ranging up to a new vehicle fuel economy improvement rate of 6% per year. For the 6%/yr scenario, the analysis projects gasoline savings of 2.9Mbd and emissions reductions of 147 million metric tons per year (carbon equivalent) of greenhouse gases and 495000 metric tons per year of evaporative hydrocarbons by 2010. The sensitivity of the projections to various factors is also examined. The most critical assumption is the baseline (i.e., the extent of fuel economy change in the absence of stronger standards). Other factors examined, such as growth in vehicle miles of travel (VMT), VMT rebound, credits toward regulatory compliance, rollbacks of standards, upper and lower bounds on a percentage increase standard, possible vehicle market shifts and fuel economy shortfall, were found to have smaller effects. Fuel economy standards are projected to be a reliable mechanism for controlling future gasoline consumption and associated pollution emissions in the United States.