The U.S. Environmental Protection Agency (EPA) and California's CARB are widening the Volkswagen investigation into several more expensive VW, Porsche, and Audi automobiles with 3.0-liter diesel engines in model years 2014 through 2016. Volkswagen says it installed no defeat device software on its 3.0 litre V6 diesel cars and is cooperating with the agency to fully investigate the matter.