WASHINGTON -- The average fuel efficiency of U.S. cars and trucks sold in the 2006 model year showed no improvement from the year before at 25.4 miles per gallon, as increased sales of fuel-thirsty cars offset slightly more efficient trucks, according to federal data.
The figures -- the first new data in two years -- will likely add to the push in Washington for higher efficiency standards. Several lawmakers want to require U.S. automakers to meet steep annual increases in fuel economy rules.
Detroit automakers turned in a mixed performance, with flat to lower results for cars and only DaimlerChrysler AG posting a gain in truck efficiency.
Toyota Motor Co. and Nissan Motor Co. raised their averages for their North American-built cars and trucks, while Honda Motor Co.'s figures held steady in cars but fell for trucks.
DaimlerChrysler's domestic car fleet fell to 25.7 m.p.g., from 28.8 m.p.g., the largest decrease among the top six automakers. With sales of vehicles such as V8-powered models of the Chrysler 300 sedan, DaimlerChrysler was the only full-line automaker to fall short of the fuel-economy standard for passenger cars.