Photos: 2008 GMC Yukon Hybrid

GM's first full hybrid is a massive SUV, revealing the company's efforts to revive the flagging SUV market. The Yukon Hybrid is designed to pull trailers and boats while hauling cargo and people, all while getting around 20 mpg.

Although its powertrain is unique, the Yukon Hybrid uses the same body, chassis, and interior electronics as its standard-engine counterparts.

The gas engine in the Yukon Hybrid is a 6-liter V-8. It uses cylinder deactivation, which can reduce it down to four cylinders, under certain low-load driving conditions. But the hybrid system, integrated through the transmission, gives the vehicle its excellent city mileage.

There's no mistaking that this is a hybrid model. It has badges and front and rear window stickers all proclaiming its innovative powertrain. Then there's the long hybrid banner down the side.

With its hybrid system, the Yukon runs under electric power up to 30 mph under light acceleration. Under hard acceleration, you can feel the different elements of its powertrain take over.

The Yukon Hybrid has three rows of seats, handling seven occupants. The third row folds down easily, and can be removed to maximize cargo space.

The cabin offers plenty of room, with high trim appointments, such as leather seats, full climate control, and a standard navigation system.

The steering wheel has cruise controls on the left and audio controls on the right, with volume buttons hidden behind the selection buttons. These buttons could be better integrated with the wheel.

The gauges are one sign that this is a hybrid. The tachometer includes and Auto Stop reading, which shows when the car's engine automatically turns off.

The navigation unit sits under a single CD slot, both of which are standard in the Yukon Hybrid. The car also has OnStar, for hands-free calling and extra navigation help.

The power flow animation shows the different elements of the hybrid system. Underway, it shows when power is going from the battery and engine to the transmission.

We really like how easy it is to go from the full map to this split-screen view.

You can input multiple destinations with the navigation system. Destination entry is somewhat limited, with points of interest and manual address entry as the main options.

The map resolution isn't great, and the navigation system lacks advanced features, such as traffic reporting or text-to-speech.

The interface is excellent for selecting music from MP3 CDs. The system can also scan an MP3 CD and let you select music by artist, album, and genre.

XM satellite radio is also standard. This interface is easy to use, and includes six sheets of presets that can mix and match FM, AM, and XM radio stations.

A nine speaker Bose audio system comes standard in the Yukon. It does an adequate job filling the big cabin, but it's far from the best we've heard.

A rear-view camera is also standard in the Yukon Hybrid, a necessary feature, due to the car's size.