Photos: Production hybrids

The 2009 Chevrolet Silverado Hybrid makes use of GM's 2-Mode technology, which features two electrically controlled variable transmission (ECVT) modes that change based on the car's speed and engine demand. The result is a 25-percent improvement in fuel efficiency relative to the gasoline-only Silverado, according to GM.

Not only does the Malibu get an all-new body style for 2008, it also gets an available hybrid power train. Unlike the 2-Mode hybrid system that GM is using in its full-size trucks, the Malibu gets GM's Belt Alternator Starter System (BAS), found in the Saturn Vue and Aura Green Lines. The BAS replaces the car's conventional alternator with an electric motor/generator and adds a nickel-metal hydride battery pack.

Like the Saturn Green Line hybrids, the Malibu Hybrid features regenerative braking, early fuel shutoff during deceleration, and an autostop function for cutting the engine during idling. All this adds up to an EPA rating of 24 mpg city and 32 mpg highway.

The Cadillac Escalade is one of the last cars we associate with environmental consciousness, but the Big Daddy of Caddies showed some green credentials at last year's L.A. show. The Escalade Hybrid shares its power train with the Silverado, Yukon, and Tahoe Hybrids and gets more than a 50-percent improvement in fuel economy in city driving, according to GM. The Escalade Hybrid is distinguishable by its unique grille, new exhaust system, and "Hybrid"-branded fender louvres. Like its 2-Mode Hybrid stablemates, it can run solely on electric power.

Like GM, Chrysler is thinking big for its hybrid lineup. The Aspen and Durango Hybrids are both motivated by a 5.7-liter HEMI V-8 engine, which is mated to a two-mode hybrid transmission. Thanks to its low- and high-speed electronically continuously variable transmission and two AC synchronous electric motors, the Aspen can be run at low speed solely on electric power. At higher speeds, the electric motor can be used to assist the combustion engine for acceleration or towing.

The Durango Hybrid makes use of the same HEMI V-8 and two-mode hybrid system that's in the Aspen Hybrid, which give it 385 horsepower. Both models also feature regenerative braking, which converts the car's kinetic braking energy into electricity that is used to recharge an onboard nickel-metal hydride battery pack.

While BMW showed off its X6 ActiveHybrid as a concept car, it is almost certain to make it to production. Thanks to its two-mode active transmission with an integrated electric drive system, the hybrid version of BMW's "sports activity coupe" delivers a 20-percent improvement in fuel economy compared with its gasoline counterpart.

Another product of the two-mode hybrid joint development program, between Mercedes-Benz, BMW, and GM, the ML450 hybrid will come on the market in 2009, potentially making it a 2008 model. At the same time, Mercedes-Benz will bring out a hybrid S-class, which could be the first sedan to use the two-mode hybrid system.

Porsche promises a hybrid version of its Cayenne SUV will be available by the end of the decade. The company is already testing prototypes of this car, using a hybrid system developed independently. Porsche can claim a lot of history with hybrids, as Dr. Ferdinand Porsche built a hybrid car in 1900.

With the gasoline-powered GLK entering production next year and the Mercedes Bluetec Hybrid system set to debut in 2010, we wouldn't be at all surprised to see this crossover make it to showrooms by the end of the decade. The GLK Bluetec Diesel Hybrid relies on a 2.2-liter diesel engine mated to an electric motor to give a reported average fuel economy of 40 mpg.