Fuel economy of vehicles sold in the U.S. last year had the sharpest gains in almost four decades, as foreign automakers Honda Motor Co. Ltd., Volkswagen AG and Mazda Motor Corp. had the most efficient fleets, Bloomberg reported. An annual report by the U.S. Environmental Protection Agency (EPA) showed that new cars and trucks had a 16 percent gain in fuel efficiency in the past five years, to 23.8 miles per gallon. Preliminary data shows an average increase of 1.4 mpg in 2012 from the previous year, which in part was attributed to the drop in Japanese vehicle production after the March 2011 tsunami, the EPA said. Read more.