Average fuel economy for model year 2004 cars and light trucks are estimated to average 20.8 miles per gallon, the Environmental Protection Agency reported this week. Average model year 2004 fuel economy for cars is 24.6 mpg and 17.9 mpg for light trucks. The 20.8 mpg average reflects a trend of relatively constant fleet fuel economy over the last eight-years, though it is 6 percent lower than the peak of 22.1 mpg achieved in 1987-88. Growth in the light truck market, which includes SUVs, vans, and pickup trucks, accounts for the sluggish increase in fuel economy. Light trucks are projected to make up 48 percent of the U.S. market, more than twice their market share in 1984. The SUV market share increased from less than two percent of the market in 1975 to 25 percent of the market now. In that same period, the market share for passenger cars decreased from 81 to 52 percent. While fuel economy levels have been relatively unchanged recently, vehicle performance has improved as manufacturers continue to respond to consumer demands. Honda Motor Co.’s U.S. fleet is the most fuel-efficient. To compare fuel economy of 2004 models, click here