Without seeing the Hybrid badges or decals, you might not even know that it's so green; for light-duty use, the Sierra Hybrid performs much like a standard version of the GMC Sierra 1500 with one of its two smaller V-8 engines (4.8- or 5.3-liter). But within, the Sierra Hybrid has a powertrain that's out of the ordinary: a two-mode hybrid powertrain, mating an all-aluminum 6.0-liter V-8, with variable valve timing and Active Fuel Management, to an electrically variable transmission (EVT) that packs two electric motor/generators and four fixed-ratio gears. Total output is 332 horsepower and 367 pound-feet of torque—which means that the Hybrid can accelerate about as quickly as the 5.3-liter.
About the only thing you lose in the Hybrid is the standard model's under-seat storage in back; that's where the 300-volt nickel-metal-hydride battery pack is stowed.
For more on the Sierra truck line's wide range of cabs, beds, and trims, plus information about features, safety, and comfort, see our full review of the 2011 GMC Sierra 1500.