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2008 GMC Yukon Hybrid (21.5 MPG) Review

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A Tree Hugger’s Dilemma –
Is It Good or Is It Bad?
By Steve Purdy
Detroit Bureau

Our timing was good for a thorough test of the new GMC Yukon 2-Mode Hybrid since we have a trip to Chicago planned to haul some furniture to my daughter in Andersonville. Our friend, Paul, is sharing the ride to go visit his two daughters who both live not far from mine. As a bonus this week the annual Taste of Chicago food festival downtown will tease our palates. My daughter and one of Paul’s are chefs and therefore foodies, so we’ll not want for gustatory entertainment.

Most car-based hybrids (Prius, Accord and the like) get significantly better mileage in congested city driving than on the open road. I see that the Yukon is rated at 21-pg in the city and 22 on the highway. We’ll see how that shakes out in the next couple of days. My son-in-law, Mike, commutes from Andersonville (near the big lake) to his office near O’hare Airport – usually at least 45 minutes - in his new Camry Hybrid and regularly gets over 40-mpg. His commute is often stop-and-go most of the way so his is the ideal use of Toyota’s 2-mode hybrid system in a mid-size car. This 2-mode is powering a massive SUV so there may be some compromises.

But, isn’t it incongruous, you ask, to have an ostensibly eco-friendly hybrid power system in a big, ostentatious SUV? Perhaps not.

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GM’s philosophy regarding the application of hybrid technology is a bit different than some. Product boss, Bob Lutz, told a group of us a few years ago at the Detroit Auto Show that GM would focus hybrid technology first on large vehicles, like busses and large SUVs, where the most fuel savings could be realized. After all, converting a little car to a hybrid propulsion system results in about a 30% fuel savings and converting this full-size, truck-based SUV makes a 50% improvement over the standard gasoline powered vehicle. Which one saves the most fuel? Well, we could do the math a number of ways, I guess.

GM first successfully used this two-mode hybrid in big busses. We rode in one at the Chicago Auto Show a few years ago and, as a former bus driver I can attest that it is amazingly fast in that huge vehicle. And they claim a huge reduction in fuel consumption.

Now, before you begin to diss all big SUVs just realize that some people need them to tow big stuff, haul extra people and cargo, or just fit into the lifestyle they are, so far, still entitled to determine for themselves. There is no question we and our families are safer in that big, heavy beast as well, are we not. Until we decide as a society that a vehicle buyer is not allowed to make that choice for him/herself there will be a market for these luxurious trucks. Adding substantial efficiency is a good thing, I contend.

I have no trouble loading a chest of drawers, a dresser and the dresser’s mirror in the rear cargo area of our Yukon. I pulled out the two third-row seats with a pull of a strap and a jerk on a sturdy handle. I must say, those are heavy buggers at 63.5 pounds apiece. With all three rows of seats in position we have a decent 16.9 cubic-feet of cargo area. With the third row out we have a substantial 60.3, and with the 60/40 second row folded as well a huge 108.9 cubic-feet opens up. In this case we travelers are three so I leave the 40 side of the second row up and fold the 60 to accommodate the length of the dresser.

The rest of the interior is well-designed and mighty luxurious. Generous leather seats are comfortable and appear of excellent quality. Fit and finish are excellent as well and with all that full-size SUV room in there I felt like a potentate. Though if I were one I guess someone else would be driving. I wouldn’t want to spend a lot of time in that knees-in-your-chin third seat where the floor is high. If you regularly must accommodate extra passengers you’ll be better off with a minivan or other large crossover, like the GMC Acadia (our test vehicle next week - watch for a comparison.)

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Like most GM products the controls and gauges are easily managed and read. I didn’t have to go to the manual for anything. My only criticism inside is that when the navigation screen is in full-map mode we have no clock. Air bags protect passengers at all seating positions and the Yukon has earned maximum ratings from NHTSA for frontal and side crash protection. It has not been rated for rollover.

This GMC Yukon Hybrid is a good compromise – or appeasement, if you prefer. Fuel mileage is equal to many cars and, while you’re still directing a huge mass (over 6,000 pounds empty) down the road, sitting high and taking up a lot of real estate, you’re safe, secure and basking in the lap of luxury. Isn’t that the American way?

My pretty blonde ensconces herself in the rear seat. She likes to use long drives as an opportunity to catch up on her magazine reading. Friend Paul climbs in up front with me. His first criticism is that the grab handle would be handier if it were above the door rather than secured into the A-pillar. I expect its position is partly dictated by the full-curtain air bags above the door. Besides, Paul is a tall fellow and I expect a shorter person would prefer it where it is – within shorter reach.

If it weren’t for the brash graphics and ornamentation proclaiming “Hybrid” all over the outside and a couple of gauges and screens inside you couldn’t tell this one from a regular Yukon. With all the animosity out there against driver’s of big SUVs I guess owners want to advertise their environmental consciousness. A “Hybrid” graphic runs the length of the truck about three inches high on both sides just below the belt line, a decal on both the front and rear glass proclaims the same and a half-dozen pretty green badges are strewn about the exterior.

Even its weight is not much different than a regular Yukon in spite of some mighty heavy nickel-metal-hydride batteries under the second row seat and electric motors, thanks to some serious weight loss engineering, like aluminum hood and lighter wheels. Front and rear fascias, I understand, are a tad different and significant undercarriage streamlining has resulted in an amazing coefficient of drag of just 0.34.

So, how ‘bout this wonderful two-mode hybrid system codeveloped with Chrysler, BMW and Mercedes. It can, as the name implies, run on either the electric or gasoline power system or a combination, thanks to mysterious (to me at least) electronic sensors and computer programming. Two big electric motors reside within the transmission which works rather like a CVT (continuously variable transmission) but without belts or bands like a conventional CVT. Four speeds are preprogrammed in so it acts like a conventional transmission for towing. The entire package is not much larger than a conventional automatic transmission.

These two power systems together - the 332 horsepower, Generation IV 6.0-liter V8 engine with 367 pound-feet of torque, boosted by two big 80-horsepower electric motors - make for plenty of grunt in any situation. Towing capacity is 6,000 pounds just like the regular Yukon. Cylinder deactivation allows the engine to run on 4 cylinders under light load and regenerative braking puts juice back into the batteries on braking.

We experience the power while passing on a two-lane in rural Indiana - a breeze with both systems working together. Our friend, Paul, thought the acceleration amazing, as did I. After all, this is a huge, heavy luxury truck. Of course, most of the time we weren’t pushing hard but when we needed thrust we just had to put the right pedal down hard.

Handling is about what we would expect from a large, truck-based SUV, that is, a cloverleaf entrance ramp is not its forte. The ride, though, is excellent. Steering is light but precise and quick enough. It really is a pleasure to drive. It doesn’t feel cumbersome or awkward. The standard back-up camera adds a bit of confidence for drivers not used to a vehicle this size who are backing, parking and maneuvering in small spaces.

Our Silver Birch Metallic test truck shows a base price of $50,045 inclusive of a lot of stuff that may be extra on the base Yukon, like the navigation system and lots of leather. The official GM Web site shows the base price to be $50,945 – probably a matter of a change in standard features. Our only option is the power sliding sunroof for $995. With the $900 destination charge our sticker shows $51,940, but I’ll bet with big vehicle sales in the crapper there are probably some deals to be had out there in the real world.

Even though the components are substantially more complex and costly GM still provides their 100,000-mile powertrain warranty. The bumper-to-bumper coverage is 3-years and 36,000 miles. That’s pretty much the minimum in the industry.

By the way, this Yukon Hybrid beat out in the Malibu, Nissan Altima, Mazda Tribute and Saturn Aura hybrids for Green Car of the Year honors presented by the respected Green Car Journal, to which this reporter subscribes. It also won Popular Mechanic’s Auto Excellence Award in the Fuel Economy category.

So, our trip to Chicago plus normal driving around here resulted in an average of 21.5 mpg for the week – just what the EPA predicted. Impressive, I say. I’m sure there are many in the audience who will still diss the Yukon just because of its size. Not me. I love that whole package.

Steve Purdy, Shunpiker Productions, All Rights Reserved