By Justin Pritchard
GM has been developing a large-SUV hybrid drive system in cooperation with Chrysler and BMW. Teaming up helps spread development costs across three different automakers, and the resulting Two-Mode hybrid system is already available to Tahoe and Yukon buyers. It's an innovative partial electric drivetrain that allows the huge haulers to consume as little fuel as a mid-sized sedan.
2009 Chevrolet Silverado Hybrid
The technology will soon make the leap from SUV's to pickup trucks. GM has already announced the upcoming availability of the GMC Sierra Hybrid and Chevrolet Silverado Hybrid models, which promise buyers the power of a hefty six-liter engine combined with a hybrid drive system for fuel savings. GM says the new hybrid pickups offer the handsome looks and power owners are used to, while offering a 25 percent reduction in fuel consumption.
All-electric driving is possible at speeds under 30 miles per hour courtesy of the Two-Mode hybrid system. At low speeds and under low-load, the gas engine can go to rest completely, allowing the truck to be driven solely on battery power. This uses no fuel, emits no emissions and is completely silent.
When the accelerator is depressed, Sierra Hybrid's 6.0 liter V8 instantly goes to work to deliver a familiar sound and acceleration. The V8 engine helps the Sierra Hybrid along at highway speeds, while employing some fuel-saving technologies of its own. These include Late Intake Valve Closing (LIVC) to help in the emissions department, and Active Fuel Management to de-activate cylinders when appropriate.
The latter feature allows the engine to put cylinders to 'sleep' when not needed- allowing the big V8 to boast smaller-engine fuel consumption in certain situations. Sierra hybrid also gets a specially tuned exhaust system which takes the hybrid powerplant's unique characteristics into consideration.
GM says the Sierra and Silverado Hybrids will allow owners to realize a fuel savings even when the truck is fully loaded or towing a trailer. The hybrid hardware will be sold on crew-cab bodied trucks in two and four wheel drive. A stability control system, trailering package and locking rear axle are standard on hybrid models, and towing capacity is 6,100 lbs.
2009 GMC Sierra Hybrid
Jim Bunnell, GMC general manager, comments on the Sierra Hybrid model. "The Sierra Hybrid represents GMC's commitment to engineering excellence, delivering a fully functional truck that offers a significant improvement in fuel economy. Sierra Hybrid will deliver fuel economy that is expected to be the best in the full-size pickup segment, exceeding the current mileage leader - the non-hybrid Sierra."
The Silverado and Sierra hybrid twins go on sale later this year.
