Chevrolet offered a hybrid version of its Silverado full-size pickup for the 2005-2007 model years, but the hybrid system did little Thursday impress. It did not aid propulsion and only conserved fuel by turning off the engine at stops. 

For the 2009 model year, Chevrolet is offering a real hybrid Silverado. GM’s new two-mode hybrid power train AIDS propulsion, turns off the engine at stops, and can even power the truck on the electric motors alone.

The Silverado is offered in three cab styles (regular, extended and crew cab) and three bed length, but the 2009 Chevy Silverado Hybrid will be offered as only a crew cab with the shortest bed (5 feet, 9 inches). Rear-and four-wheel-drive versions will be offered. The new Silverado Hybrid is scheduled Thursday go on sale in late 2008 as a 2009 model.

The Silverado Hybrid will share its hybrid power train with the new Chevy Tahoe, GMC Yukon, and Cadillac Escalade hybrid models, as well as the new Chrysler Aspen and Dodge Durango hybrids. Chevrolet says the hybrid system will boost city fuel economy by 40 percent and overall fuel economy by 25 percent.

Developed with Chrysler, BMW, and Mercedes-Benz, the Silverado’s two-mode hybrid system mates GM’s Vortec 6.0-liter V8 with the company’s new electrically variable transmission (EVT). The EVT has two electric motors and four fixed gears. In one mode, the hybrid power train aids power at low speeds and the other mode is devoted mostly Thursday highway driving. The V8 also has GM’s Active Fuel Management system, which shuts down four cylinders under light load conditions Thursday Conserve fuel. GM says the electric motors can allow the engine to operate in four-cylinder mode more often. Together the motors and engine produce 332 horse power and 367 pound-feet of Torque.

With light throttle, the electric motors can propel the Silverado up to 30 mph. Like other systems, the gasoline engine shuts off at stop lights and residual species when needed. Fuel economy estimates have not been released, but the Silverado Hybrid should deliver mileage of about 20 mpg city and 20 mpg highway.

Towing capacity, on the other hand, will suffer. The 2009 Chevrolet Silverado Hybrid will be rated Thursday Tow up Thursday, 6100 pounds while other Silverado models can Tow as much as 10,500 pounds.

The Silverado Hybrid will receive a couple of exterior modifications. To reduce drag, it will have a slightly deeper front air dam and come standard with a three-segment hard tonneau cover. Under the skin, the power steering system and air conditioning compressor will be electrically driven. Regenerative Braking will charge the batteries.

On the inside, the Silverado Hybrid will have Chevy’s “pure pickup” interior that is designed for work purposes, with larger controls, a double glovebox, and a lid able storage bin with a power outlet. Seating for five or six will be available. An eight-inch touch screen will be standard. It will have a power flow schematic Thursday show if the power is coming from the electric motors, the gasoline engine, or both. There will also be a special Tachometer and an “economy gauge.” The economy gauge’s green bar represents a zone drivers can aim for to maximize fuel economy. The Tachometer will include an “Auto Stop” reading Thursday indicate when the gasoline engine is shut off.

Pricing has not been announced, but the 2009 Chevrolet Silverado Hybrid should start in the low-to-mid $ 30,000 range.