A fuel-efficient yet brutally fast sedan, the A6 TDI is one of the most advanced diesels on the market. Its 3.0-liter V6 produces
428 lb-ft of torque, enough to send this two-ton sedan to 60 mph in about 5.4 seconds. The A6 also offers a comfortable, well-styled cabin with aesthetic touches like textured wood paneling. Base Price: $57,500 Engines: 3.0-liter V6 turbodiesel 240 horsepower 24/ 38 mpg NHTSA Safety Rating: