The brand-new Volkswagen Jetta TDI diesel took the Green Car of the Year award at the 2008 Los Angeles Auto Show. The Jetta TDI won based on its high fuel efficiency numbers—41 mpg on the highway and 30 in the city—and its price point of $21,900. The high-mpg and low cost gave the Jetta TDI the upper hand—“market significance” is a key criterion for the award—as it bested the more expensive BMW 335d (also an oil-burner,) as well as the Ford Fusion Hybrid, Saturn Vue Two-Mode Hybrid, and the diminutive Smart car.

The Jetta TDI may not need the publicity boost that comes from an award, since VW has said it is virtually sold out at all dealerships. According to the company, many dealers have started to form waiting lists.

Joining the Jetta at the show on the VW stand was the Touareg V6 TDI, with fuel economy numbers of 17/25 mpg. The Touareg TDI, priced at $42,800, goes on sale in January 2009. BMW introduced two clean diesels in Los Angeles—the 335d sedan mentioned above, and the X5 xDrive35d SUV. The 335d goes on sale in December with the X5 following in January. BMW gave strong hints that it would be bringing more diesel models to the US in the coming years.

At the Audi stand, a quartet of diesels from the recent Mileage Marathon were showcased, highlighted by an A3 2.0-liter diesel that turned in a high of 50.6 mpg during the cross-country driving program. The US-spec version of that model is rated at 39 mpg. A version of the A3 is likely to join the Audi US fleet in fall of 2009, joining the Q7 3.0L TDI that goes on sale in January and a future A4 3.0L TDI.

Mercedes-Benz showcased its three diesel SUVs currently on the market: the ML320, R320 and GL320. In addition, the company introduced the Fascination concept coupe, powered by a supercharged 2.2-liter 4-cylinder BlueTEC diesel that puts out 204 horsepower. With fourth generation common rail diesel technology that raises injection pressures, the engine demonstrates how a 4-cylinder diesel could replace the standard V-6 in its class. The concept is also seen as a glimpse into the styling of an upcoming E-class coupe.

Even though they didn’t hold a press conference and haven’t said much about the promise of diesel, General Motors displayed its Opel Flexstreme. The Opel, a European answer to the Chevy Volt, is a plug-in series hybrid electric vehicle that uses a small diesel engine to recharge batteries—only after the fully charged vehicle has run for 40 miles on electricity without help from petroleum of any kind.