2009 Chevrolet Silverado Hybrid

At that point, the Silverado's 332-horsepower, 6.0-liter V-8 gasoline engine steps in. The electric motors lend a hand, though, so the engine uses only four cylinders much of the time. A complex two-mode transmission switches between continuously variable mode (for most driving) and four-speed mode (for highway driving and other steady-speed use).

The 2 Mode hybrid system works quietly, and most testers say fairly seamlessly, but Christopher Jensen of The New York Times finds that the motor's speed suddenly changes for no reason sometimes while driving under 30 mph. GM says engineers are working to fix the problem. Josh Sadlier at Edmunds.com says the system hesitates obviously while it accelerates, as the various components kick in.

The Chevy Silverado Hybrid's regenerative brakes, which recapture energy while you brake, irritate some testers. Braking distances are long, and "there's a delay in actual braking force when you apply the pedal, and then they get grabby," says Kavanagh at Edmunds Inside Line. Car and Driver tester Erik Johnson finds the Sierra Hybrid's brakes "mushy," but he thinks drivers would get used to it.

GM's 2 Mode hybrid pickup trucks can't tow as much as other full-size pickups (6,100 pounds max) because their cooling capacity is limited. General Motors says its next-generation hybrid pickups, due in 2013, should offer 50 percent better tow capacity. "Still, when loaded within its limits, the hybrid pulls just like a diesel heavy-duty pickup," says Mike Levine, editor of PickupTrucks.com in his review of the Sierra Hybrid. "We think GM's half-ton hybrids are the best light-side-of-light-duty towing rigs out there."

Fuel efficiency and safety ratings

The GMC Sierra/Chevy Silverado hybrid easily takes first prize for fuel efficiency among full-size pickups, especially in city use. Expect 21 mpg in mixed driving with rear-wheel drive (21 mpg city and 22 mpg highway) or 20 mpg in any kind of driving with four-wheel drive, according to the U.S. Environmental Protection Agency. Some real-world tests bear that out, but Kavanagh manages only 17 mpg in his brief test. By comparison, a full-size Ford F-150 pickup (*Est. $21,565 to $44,355) with its base gasoline engine gets an estimated 17 mpg in mixed driving (but only tows a max of 5,900 pounds), and a compact crew-cab Toyota Tacoma (*Est. $15,170 to $27,075) equipped with the optional V-6 can get an estimated 18 mpg and even tow slightly more (6,500 pounds) than the Chevy Silverado Hybrid and GMC Sierra Hybrid. Either would cost thousands less than the General Motors hybrid pickup trucks, even counting the $2,200 federal tax credit for hybrid vehicles that the GM hybrid trucks are eligible for.

The Chevy Silverado Hybrid 1HY (*Est. $38,020 to $41,170) seats six with front and rear bench seats, and it comes well equipped with dual-zone climate control, a leather-wrapped steering wheel, soft tonneau cover and more. The Silverado Hybrid 2HY (*Est. $44,155 to $47,305) seats five, with leather front bucket seats and a rear bench. It includes more upscale features, such as a navigation system and hard tonneau cover. Both trim levels come with a 5-foot-9-inch cargo bed and choice of rear-wheel or four-wheel drive.

The Silverado Hybrid gets perfect five-star crash ratings and four-star rollover ratings in government tests conducted by the National Highway Traffic Safety Administration. It hadn't yet undergone independent crash testing at the Insurance Institute for Highway Safety when we checked. However, the gas-powered Chevrolet Silverado 1500 (*Est. $19,375 to $41,355) on which the hybrid is based gets a "poor" rating in IIHS's side crash tests (which mimic a pickup truck hitting the Silverado, instead of the car-size barrier the government uses in its crash simulations). In such a 31 mph side crash, people in a 2009 Chevy Silverado 1500 are more likely to suffer fractured ribs and/or internal organ injuries, and possibly serious neck injuries, even with optional side airbags.

We found no reliability predictions for this new model. The Chevrolet Silverado Hybrid carries a three-year, 36,000-mile basic warranty and five-year, 100,000-mile powertrain warranty. All GM and Chrysler warranties are now backed by the U.S. government, which will become the majority stakeholder in General Motors once it exits the Chapter 11 bankruptcy proceedings it entered on June 1, 2009.

Several reviews of the new Chevrolet Silverado Hybrid are based on brief test drives at the truck's San Antonio press launch event. However, they are still thorough enough to point out several obvious benefits and flaws with the design, including reviews at AutoblogGreen.com, Car and Driver, Edmunds Inside Line, Edmunds.com and The New York Times. PickupTrucks.com tests the GMC Sierra Hybrid instead, but readers can apply the results to the Chevy Silverado Hybrid; aside from slightly different exteriors, the two trucks are identical (like their conventionally-powered counterparts). We found fuel economy estimates at FuelEconomy.gov and crash-test ratings at the SaferCar.gov. Another crash-test organization, the insurance industry-funded Insurance Institute for Highway Safety, hasn't yet tested the Silverado hybrid, but it gets disappointing results with the very similar gas-powered Silverado.