2008 GMC Yukon

Full-size SUVs are better known for their thirst for fuel and heavy impact on the environment, but the all-new GMC Yukon Hybrid and its Chevrolet Tahoe counterpart are making a bold statement this year thanks to their all-new 2-Mode Hybrid technology.

I recently drove the 2008 GMC Yukon Hybrid and can vouch that this new system is quite remarkable. This isn't a mild hybrid. GM's 2-Mode Hybrid system is fully capable of propelling the Yukon in full electric mode at speeds up to approximately 25 mph.

Better yet, Yukon's gasoline-powered V-8 engine does not need to stay running while stopped in traffic to keep the air conditioning blowing cold. That's because there's an electrically-operated air conditioning compressor that keeps the cabin cool regardless of whether the gas engine is online or offline.

The 2008 GMC Yukon Hybrid can be had as a 2WD or 4WD model. My 2WD tester was rated at 21/22 mpg city/highway. While that may not seem all that impressive, just ask any owner of a full-size SUV. They'll likely say that 12/18 mpg city/highway is closer to reality.

In fact, my 2008 GMC Yukon Hybrid 2WD betters the less-powerful non-hybrid Yukon (5.3-liter V-8) by 7 mpg city and 2 mpg highway.

I don't expect these numbers to sway car buyers into considering a SUV for their next purchase, but for those that need the size and/or hauling power of a full-size SUV should take a serious look at a hybrid like the GMC Yukon.

By the way, towing capacity for the 2008 GMC Yukon Hybrid 2WD is 6,200 pounds and the 4WD model is rated at 6,000 pounds.

The 2008 GMC Yukon Hybrid's exterior is distinguishable from the non-hybrid thanks to "Hybrid" badging and aerodynamic improvements that include a lowered air dam, shaped running boards and special rear-end treatments.

Inside the cabin accommodates up to eight passengers. There's a long list of standard equipment including a rearview camera for backing, touchscreen navigation system with Hybrid power display, tri-zone automatic climate control, leather upholstery and more. A sunroof and rear-seat DVD system are the only options.

Those that need space to haul gear will want to remove the heavy and bulky third-row seat as it does not fold flat into the floor.

Under the hood of the 2008 GMC Yukon Hybrid is a large 6.0-liter V-8 gasoline engine that employs variable valve timing and GM's Active Fuel Management System that allows the V-8 to save fuel by shutting off four of its cylinders during steady cruising.

You would think that you could actually feel this happening but it's imperceptible. Other than the display informing me of four-cylinder mode, I could not tell. And power comes online quickly when you press the accelerator to pass other vehicles.

The two electric motors that power the 2008 GMC Yukon Hybrid are located within the electrically-variable transmission. The transmission can provide varying ratios for low-speed, light-load operation and fixed ratios for high-load operation.

While driving around town, I purposely accelerated lightly most of the time in an effort to remain in full electric mode. It's an eerie feeling being in a large SUV and not hearing or feeling the humming of the engine.

Of course the Yukon Hybrid employs regenerative braking, too. That means when your braking, the electric motors become generators to slow the vehicle down and recharge the 300-volt battery pack.

Brake pedal feel is quite like most other large SUVs but most of the braking is regenerative and not done by the old friction units at each wheel.

Overall, the truck's mannerisms are quite nice and there's no herky-jerky feel when the gas engine goes offline or comes online. All of the hybrid components are warranted for 8 years or 100,000 miles.

However, with a starting price at the $50k mark, it may take some time to recoup your investment, especially when you consider the huge incentives on the non-hybrid versions.

2008 GMC Yukon 2WD Hybrid
Engine: 6.0-liter (332 hp) V-8 and 300-volt battery pack powering two 60-kilowatt electric motors

Transmission: Electrically-variable w/four fixed gears

Drive type: 2WD

Fuel economy: 21 city/ 22 highway

Base price: $50,045

As tested: $51,940 (includes $900 for destination)

Web site: www.gmc.com