U.S. motorists are opting for larger, more powerful cars with worse fuel economy in response to the sharp drop in gasoline prices. The average fuel economy for vehicles sold in the United States in September was 25.2 miles per gallon, down by 0.6 mpg since August 2014, according to the University of Michigan Transportation Research Institute. “The decline likely reflects the decreased price of gasoline in September and the consequent increased sales of pickup trucks, sport-utility vehicles and crossovers,” the institute said. Fuel economy, using window-sticker values, has increased by 5.1 mpg, about 25 percent, since October 2007, when the institute began monitoring, thanks to higher fuel prices and tougher government standards. But the improvement has stalled as the reduction in fuel prices has encouraged buyers to trade efficiency for increased size […]