Volkswagen has flirted with high-mpg hybrid and sub-compact concept cars, but the company’s most compelling green car option is clean diesel. The brand-new Volkswagen Jetta TDI diesel—clean enough to pass California’s strict standards for tailpipe emissions—offers 41 mpg on the highway and 30 in the city. A number of real-world tests have blown past those numbers. Unlike gas-electric hybrids, clean diesels can be pushed hard and still earn those high-mpg numbers. With a price tag of $21,900—and a federal tax credit of $1,300—the Volkswagen Jetta TDI offers a lot of mpg for the buck. The vehicle, available as a sedan or wagon, took the Green Car of the Year award at the 2008 Los Angeles Auto Show. Mercedes, BMW and Audi—all luxury carmakers—are also vying for clean diesel customers, but Volkswagen appears to be the only carmaker aiming at maximum mileage at a minimal cost. That’s a winning combination. See our list of Volkswagen cars and read the latest news about Volkswagen’s fuel efficient models.