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2010 GMC Yukon Hybrid Review


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"For those who often transport eight adults and/or tow a boat or trailer, the 2010 GMC Yukon Hybrid gives the kind of savings that makes profitable sense. "

2010 GMC Yukon Hybrid
by Thom Cannell
The Auto Channel
Detroit Bureau

Count me a naysayer when it comes to hybrids—most of the time.

A small car like a Toyota Corolla or Ford Fiesta with a 1.0-liter to 1.6-liter engine already gets terrific mileage, and adding another power train simply amplifies cost and complexity. Leaving aside governmental mandates and societal issues, small hybrids don’t make much sense to me. Hybridizing big SUVs does make sense and a GMC Yukon is really, really big with a length a tad under 17 feet and weight—the4WD version we tested weighted in at 6,185 pounds, while the svelte 2WD non-hybrid masses 5,892 pounds—measured in tons. A Yukon Hybrid retains its legendary power, in addition to size, and offers a tow rating of 6,200 pounds plus a standard eight-passenger interior.

The Yukon Hybrid package includes some unique features and the most upscale interior offered by GMC as part of its price. Heated and cooled leather 12-way adjustable front seats and leather-appointed second row seats, a Bose Surround Sound audio system, and a navigation system with rear camera and real-time XM NavTraffic are all included. The Hybrid’s exterior features a variety of aerodynamic improvements like subtle reshaping of the aluminum hood, shaving the rear behind the D-pillar to produce positive pressure and lower drag, slight lowering of the body, and low rolling-resistance tires plus unique 22-inch 8-spoke chrome wheels that contribute to less drag. Heck, only a sunroof, rear-seat DVD, or Blind Spot Alert mirrors are options.

Why does adding electric assist make sense for a Yukon?

It comes down to the physics of kinetic energy and gallons-per-mile, not miles-per-gallon. Simply put, anything that helps a large vehicle get rolling and accelerate without sucking fuel makes a huge difference in fuel economy. For instance, if you drive 10,000 miles each year a small hybrid might move your personal mileage meter by fifteen miles per gallon, moving up to an amazing 50 mpg from a paltry 35 mpg.

Wow, that just sounds huge when compared to the Yukon Hybrid which gets 20 mpg instead of 10. In reality the savings for the miniscule hybrid would be about 86 gallons per year while the Yukon would save a colossal 500 gallons. That’s right, 500 gallons of precious—and expensive—fuel. For those who often transport eight adults and/or tow a boat or trailer, that kind of savings makes profitable sense.

Under a Yukon’s aluminum hood is GM’s 6.0-liter V-8 with Active Fuel Management. AFM shuts off four cylinders whenever it can, increasing fuel economy, and that engine does most of the heavy lifting. It is coupled to the 2-Mode Hybrid system GM developed with BMW and then Daimler-Chrysler.

The coupling takes place in an Electrically Variable Transmission that stuffs two electric motors and three interactive planetary gear sets inside the transmission case. Those electric motors are powered by a 300-volt nickel-metal hydride battery hidden under the rear seat. When using only the electric drive this Yukon can accelerate—s l o w l y—to 27 miles per hour or give a boost to the engine. It’s the boost—an addition of torque to the transmission—that lets the engine operate longer in 4-cylinder AFM mode. Additionally, by managing the transient demands on the powertrain (like small grades) with electric power allows the gasoline engine to remain longer in its more-efficient four-cylinder mode.

Driving this Yukon can be like driving any other big SUV. Ignore the hybrid aspects and it will happily maximize fuel saving regardless your heavy right foot. Ahhh, but for those who want the most there is a simple energy flow gauge in the instrument cluster and an interactive display on the navigation screen to assist you. While the big power distribution diagram on the nav screen—complete with what system is using energy, what system is contributing energy, and power flow between the systems—is interesting, it takes your eyes far from the road ahead. Better to use the energy meter plugged into the normal battery gauge position.

Unfortunately that meter is small for its purpose and you will consult it often as you learn to maximize fuel economy. Well, most of you will. To get the most out of the hybrid systems requires retraining to optimize the time it operates on the battery. Accelerating on pure electric power requires that you imagine you have a raw egg between your right foot and the pedal itself; don’t break the egg. By applying very light pressure and gradually increasing speed at a rate that will infuriate bikers, runners, even Prius drivers, you can run fully electric with all amenities in operation. A more realistic option is slowing gradually, like stop-and-go traffic, to 30 and the electric motor can sustain your speed as long as you don’t change pedal position.

Lights on, stereo blasting, heater in operation, and no gasoline being burned—now that is COOL!

For our mileage testing, Detroit Editor Steve Purdy and I set the cruise control to 75 and drove from mid-Michigan to Chicago against head and cross winds strong enough to buffet the three-ton vehicle about. We got 18.7 mpg on the way there, and, after accumulating many miles of stop-and-start driving in “the loop” of midtown Chicago, we totaled 507 miles with an overall fuel economy of 19.1 miles per gallon.

The vehicle is, overall, large and comfortable, though I found the driver’s seat not as comfortable as some of the competition like Navigator. We agreed that the only cabin noise came from the Yukon’s folding mirrors and were surprised that they created more noise folded. We found the sound system to be of high quality, and of great importance, the rear doors open wide and offer easy access to the second and third row. We didn’t try sitting in the third row, which folded down easily from the open rear hatch. Nor did we try rear seat removal for maximum cargo volume. Oddly for such a large vehicle, with all three seats available for use there is only gym bag or brief case room behind the third row.

Though we appreciate the hybrid system, for this vehicle we’d like to give a 3-4.5-liter diesel engine a test drive.