2009 BMW 335d
BMW, not content to let rival Mercedes-Benz bask in the diesel spotlight, is bringing a twin-turbo, diesel-powered 3 Series sedan to all 50 of these United States late in 2008. Like its Teutonic rival, BMW uses urea injection to turn nitric oxides into nitrogen and water vapor, thereby meeting emissions regulations. The system also doesn’t need to be refilled any more often than when owners have the engine oil changed, a move by both automakers to lessen any inconvenience. BMW’s diesel is a 3.0-liter, inline-six cylinder, twin-turbo engine.