As Corporate Average Fuel Economy Standards increase, motor gasoline-related vehicle fuel economy is expected to continue to improve. The U.S. Department of Transportation's Summary of Fuel Economy Performance reports estimated increases in the average vehicle fuel economy of cars and light trucks in use at 0.5 percent per year and 0.6 percent per year, respectively, between 1999 and 2009. Advances in vehicle fuel economy have been especially pronounced in the last few years. Between 2000 and 2005, new car and light truck average fuel economy increased by 6.3 percent and 3.8 percent, respectively. Between 2005 and 2010, average new car fuel economy improved by 11.9 percent while that for light trucks increased by 14.0 percent. EIA expects average fleet fuel economy of vehicles in use to improve by an average of 0.9 percent annually in 2012 and 2013.
Higher-than-projected economic growth would likely raise highway travel and, consequently, motor gasoline consumption. However, an accelerated economic recovery may also boost new vehicle sales, accelerating the replacement of older, less fuel-efficient vehicles and improving the aggregate fuel efficiency. The accelerated replacement of cars at least 10 years old (model year 2002 or older), with an estimated average fuel economy of about 29.0 miles per gallon or less, with new cars with an estimated average fuel economy of about 34 miles per gallon, would at least partially offset the positive effects of increased highway travel on motor gasoline consumption.