The Tahoe Hybrid actually gets a larger V-8 than the standard Tahoe. Instead of the 320-horsepower, 5.3-liter V-8 and six-speed automatic transmission, the Hybrid comes with a big 332-hp, 6.0-liter V-8 and a version of the Two-Mode Hybrid system that GM pioneered with BMW, Daimler, and Chrysler. That's mated to a specially configured four-speed automatic transmission, with power supplemented by an electric motor system, and a battery pack situated under the second-row seats.
As such, the Hybrid can cruise on electric power alone up to 27 mph; at higher speeds, both the gas engine and electric power are run in parallel, and the gas engine deactivates cylinders to save gas. About the only thing that's different about the Hybrid from the driver's seat is that the electric power steering isn't weighted as nicely.
Both the Tahoe and Hybrid can be ordered with rear- or four-wheel drive, though the Hybrid uses a more sophisticated electronically controlled system that doesn't include a low range. It can tow up to 5,000 pounds.
For more information on the 2011 Chevrolet Tahoe Hybrid, see our full review pages covering the 2011 Chevrolet Tahoe lineup.