The A3 TDI gets 42 miles (67 kilometers) to the gallon (3.75 liters) on the highway, following in the footsteps, or should we say tire tracks of the Volkswagen Jetta, which won last year.
Ron Cogan, editor of Green Car Journal, said jurors were impressed with Audi's direct injection turbo diesel technology which "achieved 50 percent better fuel efficiency than the gasoline engine A3 model without sacrificing anything."
Consumers warming to climate-friendly cars
Audi sold just over 500 A3 diesels in the US in November, its first month on the market, a figure that pales in comparison to the runner-up Toyota Prius, which sold 128,000 units this year.
But Consumer Reports magazine's senior automotive engineer, Jake Fisher, said he was confident that the car would sell. "There is demand for this type of vehicle, and I think it will do well", he said, despite the traditional aversion to diesel-powered automobiles in the US.
Green car winners are chosen by a panel of Green Car magazine editors, and invited jurors, who this year included car collector and comic Jay Leno, environmental activist, Jean-Michel Cousteau, legendary muscle car designer Carroll Shelby and the head of the Sierra Club environment group, Carl Pope.