A standard Vortec 5300 5.3-liter V8 motor powers the Sierra Hybrid and a 4-speed Hydra-Matic automatic transmission coupled with the full-size truck segment’s first hybrid propulsion technology for improved fuel conservation.

The Sierra hybrid uses electric performance even less frequently. Its gas power plant can shut down when the automobile is stopped (actually, when it's braking to a stop, below 13 mph or so) and-that's it. The batteries (three 14-volt units plus the standard 12-volt) cannot power the truck at low speeds. Nor do they help out the gas power plant, which therefore can't be any smaller. It's the same 5.3-liter V-8 GM pickup buyers know and love. Because of the limited nature of this hybrid system, the benefits are mild: roughly 2 mpg in city driving and 1 mpg during the EPA's highway cycle.

The system replaces the traditional starter motor and alternator with a compact 14-kw electric induction motor or starter generator integrated between the motor and transmission. The starter generator provides fast, quiet starting power and allows the gas engine to automatically start and stop under certain conditions to conserve fuel.

The Sierra Hybrid also offers four 120-volt/20-amp electrical auxiliary performance outlets located under the rear seat and in the pickup bed. Because the 5.3-liter V-8 is the same as that in non-hybrid pickups, its performance and torque outputs are the same (295 horsepower, 325 pound-feet of torque). Acceleration, towing, and payload are undiminished. The extra hybrid gear takes up very little space-the biggest component, the three extra batteries, is under the rear seat. One interesting feature of the hybrid trucks are its four, 120-volt 20-amp AC performance outlets in the cargo bed and the rear seat; but the engine must be running in order to use them.

As in gas/electric cars, the fuel engine shuts off at stoplights to save fuel, and an electric motor restarts the motor when the fuel pedal is pushed. Unlike most gas/electric vehicles, the electric motor does not help propel the vehicle. The system does include a unique feature aimed at commercial users and picnic tailgaters: a generator that provides 120-volt performance for running electrical accessories.

Available in California, Washington, Oregon, Alaska, Nevada and Florida, the Sierra Hybrid delivers up to 10 percent better fuel economy with the same power and performance as the 5.3-liter V8. As a matter-of-fact, that same motor powers the Hybrid, producing the same 295 horsepower and 335 pound-feet of torque.

GM is not to be outpaced in this hurried race for the development of producing fuel cells. With all these amazing technological breakthroughs in the automotive industry, Partstrain stands by its commitment of delivering excellently engineered GM performance parts, replacement auto parts to go with GM's efforts of sustained production of environmently aware autos.

Browse through http://www.partstrain.com/ShopByVehicle/GMC for all of your GM auto body parts needs and have a choice in its stock of high quality and well-crafted GM accessories and performance parts. Excellent buyer service awaits you 24 hours a day, seven days a week. Partstrain adheres to rigid tests for utmost quality control and sees to it that their GM Parts do not diminish the performance of your car.

About the author:
Jenny McLane is a 36 year old native of Iowa and has a knack for research on vehicles and anything and everything about it. She works full time as a Market Analyst for one of the leading vehicle parts suppliers in the country today.