Illegal Volkswagen diesel emission systems may require two solutions

By Paul Lienert and Joseph White DETROIT (Reuters) - Volkswagen AG 's promise to fix pollution control systems on about 11 million diesel vehicles will involve changes to software, and possibly hardware, that could leave owners with cars that deliver diminished fuel economy and performance or require more maintenance, experts said Tuesday. The German automaker's new chief executive, Matthias Mueller, said Tuesday VW customers would need to have those diesel cars "refitted." The company did not s