General Motors is promising cleaner gasoline engines at the very moment Washington is making it easier to sell thirstier vehicles. The tension between those two forces, corporate pledges and looser ...

This year has been a strange one for automakers, but many of them just caught a break. The EPA effectively wiped out penalties for missing fuel-economy targets, a move that could easily trigger ...

With less regulatory pressure, engines don’t have to get cleaner or more efficient, yet GM CEO Mary Barra insists the company will keep pushing them in that direction anyway. She maintains that GM ...