Top 10 Environmentally Friendly Luxury Cars

Volvo C30 Suggested retail price: $22,700 Besides producing relatively efficient cars like the C30, Volvo spends a lot of resources on the environment behind the scenes, reducing factory emissions and recycling up to 98% of the metals used in its cars. The all-new 2008 C30's Environmental Protection Agency estimate is 18 miles per gallon city/28 mpg highway, based on a stricter EPA standard that will knock about two miles per gallon off all 2008 models. ***

Tesla Roadster Suggested retail price: $98,000 The Tesla Roadster is a battery-powered electric vehicle, expected to go on sale in the U.S. this fall. Assembled in the English factory that also builds Lotus cars, the Tesla Roadster has an original chassis, electric powertrain and body, but shares some Lotus parts. The Roadster can go from zero to 60 in about four seconds. But doing so obviously cuts into its 200-mile range on a full charge, a spokesman said. ***

Saab BioPower 100 Concept No pricing available The BioPower 100 Concept, based on the Saab 9-5 wagon, can run on 100% "biofuel," or grain alcohol. Saab says the concept car, which appeared at the 2007 New York Auto Show in April, hints at plans for a fairly ordinary "flex-fuel" U.S. model, which can run on 100% gasoline or up to 85% ethanol and 15% gasoline. ***

Mini Cooper Convertible Suggested retail price: $22,600 The retro-styled Mini Cooper Convertible is a J.D. Power and Associates pick as a "2007 Automotive Environmental Index Top Models," based on its fuel economy--an estimated 26 miles per gallon city/35 mpg highway. But it's still fun to drive, with a 1.6 liter four-cylinder engine in a small package that drives--cliché, but true--like a low-slung go-kart. ***

Mercedes-Benz E320 Bluetec Suggested retail price: $52,675 An international panel of journalists voted the diesel E-Class sedan "2007 World Green Car." The E320 Bluetec gets 210 horsepower from a 3.0-liter diesel V6, but 400 ft.-lb. of torque, the twisting power that launches the car from a standing start. In a gasoline engine, that much torque would probably require a thirsty V8. ***

Lotus Exige S Suggested retail price: $59,890 The Lotus brand is renowned in racing circles for getting the maximum amount of power for the size of the engine. The supercharged Exige S gets 220 horsepower from a 1.8-liter, four-cylinder engine and goes zero to 60 in 4.1 seconds. The 2007 model achieves an amazing 29 miles per gallon on the highway. ***

Lexus GS450h Suggested retail price: $55,615 The sporty GS450h gets 340 horsepower from the combination of a 3.5-liter V6 gasoline engine and two electric motors. The Environmental Protection Agency's estimate for combined city/highway driving is 26 miles per gallon. When the vehicle is coasting or the brakes are applied, the electric motors capture energy that would normally be lost as heat through the brakes, and use it to recharge the battery. ***

Lexus RX 400h Suggested retail price: $41,945 The hybrid drive system in the RX400h SUV has a 3.3-liter gasoline V6 engine, plus two electric motors. Together, the system generates 268 horsepower. It also has an electronically controlled, continuously Variable Transmission, which uses belts and pulleys in place of traditional fixed gears. The CVT provides a smooth ride and helps the 2007 model get around 30 miles per gallon, combined city/highway. ***

Cadillac Escalade Hybrid: 2009 Model No pricing available The hybrid Escalade is due to go on sale in the spring of 2008, and will get 25% better gas mileage than existing models. First, General Motors will introduce the hybrid powertrain in the 2008 GMC Yukon and the 2008 Chevrolet Tahoe, which go on sale this fall. The new system includes a V8 engine that uses only four cylinders under light loads. ***

Audi Q7 3.0 TDI: 2009 Model No pricing available The upcoming Q7 3.0 TDI is due in the U.S. in early 2009, probably as a 2009 model (the photo here shows a European model Q7 4.2 TDI with a bigger engine). The six-cylinder "clean diesel" is expected to have as much torque as a V8 gasoline engine. Audi will probably offer the diesel with Quattro all-wheel drive optional. ***