EPA is downplaying concerns that automakers have been slowing improvements in vehicles' fuel economy -- a key measure of their greenhouse gas (GHG) emissions -- amid fears from environmentalists that manufacturers may not be able to comply with the administration's GHG and fuel economy targets for the vehicles in model year (MY) 2016. The agency Oct. 8 issued its annual fuel economy report for light-duty vehicles that found that MY13 vehicles reached a record high fuel economy of 24.1 miles...