Audi Q7

While Volkswagen and Mercedes-Benz are the long-term diesel stalwarts in the States, relative newcomer Audi has ambitious plans. During a lengthy teleconference yesterday, Audi confirmed that it would add TDI clean-diesel models to every car it offers in the U.S. market by 2015. Audi has frequently touted the strong sales of its two current TDI models, the 2011 Audi Q7 TDI large sport utility vehicle and the compact (but aging) Audi A3 TDI hatchback. The A3 TDI is by far the more affordable of Audi's first U.S. diesels, and the company scored a coup when it was named Green Car of the Year for...