The quest for high fuel efficiency and lower CO2 greenhouse gas emissions is bringing an increasingly diverse array of ‘green’ cars to our highways. We’re seeing environmental performance becoming more mainstream in vehicles of all types, from entry level to luxury cars.

Plus, there’s greater emphasis on advanced clean diesel, which typically offers abundant power at the ready along with greater mpg. Nowhere is this more evident than with the 2010 Audi A3 TDI, which has just been named Green Car Journal’s 2010 Green Car of the Year® at the 2009 Los Angeles Auto Show.

This is the second year in a row that a clean diesel has risen to the top in Green Car Journal’s annual award program, a remarkable showing considering the competition. This year’s stellar field of nominees also includes the Honda Insight hybrid, Mercury Milan Hybrid, and Toyota Prius, along with the clean diesel VW Golf TDI, a high fuel efficiency hatchback that runs the same 2.0-liter TDI engine that powers last year’s Green Car of the Year® winner, the VW Jetta TDI.

Green Car of the Year® jurors appreciated the Audi A3 TDI’s rakish styling, upscale appointments, and 42 mpg highway fuel efficiency – a 50 percent improvement over the gasoline A3 variant that makes the car very economical to operate with low relative CO2 emissions. Plus, this compact luxury car’s quiet, 50-state certified clean diesel engine delivers substantial torque starting at a low 1,750 rpm, contributing toward a spirited and fun-to-drive nature. The A3 TDI is approved by Audi for operation on up to B5 biodiesel fuel.

Offering a wide and low stance, the handsome Audi A3 is an entry-level luxury car with an array of distinctive features. Among these are 17 inch alloy wheels, xenon headlights, LED daytime running lights, fog lights, and a standard S line exterior sport appearance. Inside, the A3 TDI’s interior offers a driver-focused design with standard leather upholstery, aluminum accents, 10 speaker concert sound system with SIRIUS satellite radio, and split 40/60 fold-down rear seats. Easy load accessibility is provided with the A3’s rear tailgate.

This year’s Green Car of the Year® jury includes six environmental and automotive experts plus a smaller number of Green Car Journal editors. Invited jurors include Dr. Alan Lloyd, president of the International Council on Clean Transportation; Carl Pope, executive director of the Sierra Club; Jean-Michel Cousteau, president of Ocean Futures Society; Matt Petersen, president of Global Green USA; automotive expert and television host Jay Leno; and automotive icon Carroll Shelby.

By all appearances a hatchback but officially classified by the EPA as a small station wagon, Audi identifies its 5-door A3 TDI as neither, preferring instead its designation as a Sportback to perhaps imply the obvious … a very fuel efficient sporty car with hatchback functionality. Regardless of how it’s defined, with a base price of $29,950 and exceptional 42 mpg highway fuel economy, the A3 2.0 TDI is well positioned to fill the needs of those seeking a sporty, fuel-thrifty, and efficient ride with luxury overtones. It’s a deserving winner of the 2010 Green Car of the Year® honor.

Gallery: 2010 Audi A3 TDI