2008 GMC Yukon

Review

If it weren't for the big Hybrid badges that have been plastered all over the

rocker panels and the glass, people wouldn't have the faintest idea that the new GMC Yukon Hybrid is more than just a regular, full-size sport utility vehicle. It doesn't take long to see the effects of the big, italicized block lettering - just keep an eye out for other drivers. Motoring down the road the driver of a silver Prius looked up at the big, burgundy Yukon with disapproval, the driver rolling her eyes only to see the hybrid badges, then smiled and waved as if I were a member of some virtuous hybrid club. Believe me, it's a shocking thing.

Admittedly, people aren't going to focus in on the fact that the Yukon Hybrid has unique bumpers and a flush underbody to help it generate a remarkably low 0.34 coefficient of drag. They aren't going to be looking out for the little green "H" that creatively incorporates a printed pattern of a circuit board as a background. No, they're looking at the size of the vehicle and its specifications, which, admittedly aren't encouraging. You get a rather big 6.0-liter V8, and, when combined with the electric assist, it makes 332 horsepower and 367 lb-ft of torque, plus it rides on a body on frame structure that was designed to haul 22'

speedboats. But then you get into the caveats. It's got an idle-stop system so it shuts off at red lights and AFM so it shut down four cylinders under light loads. And even better news is that because the electrical assist from the battery system helps to boost things along, the Yukon is more likely to run on four cylinders for a greater portion of the time.

For the most part the Yukon Hybrid works like a regular full hybrid vehicle like a Prius or an Escape Hybrid. Power from the gasoline side of the equation and power from the electrical side are combined, sent to the CVT (or more precisely the electronically variable transmission), through the transfer case (on 4WD models) and then to the drive wheels, with the ability to cruise purely on electricity factored in. In the city and at lower speeds and loads, this is what the Yukon will do. Because the battery pack has been hidden under the floor, there's no compromise on interior space or volume either.

The problem is that hybrids don't like heavy loads associated with towing or cruising on the highway. And that's where the Yukon, specifically its 2 Mode system differs from its peers. You see, inside that transmission tunnel isn't just a CVT - the housing of the standard Hydramatic transmission also stores a pair of 60 kW electric motors and actuators. When higher loads are put on the Yukon 2 Mode, it swaps into the second mode that's mostly gasoline-based, and uses four fixed ratios like an automatic transmission that mostly bypass the electric motors for greater efficiency. If you need a little extra oomph the electric motors can (and will) kick in, but for the most part it's the V8 engine flexing its muscles. It doesn't sound like much, but this is what allows the Yukon to function as an eight-seater, 6,200 lb towing machine. Nothing less would have made the cut.

Playing a supporting role to the batteries, electric motors and so on is a strict weight loss program. The components that make up a hybrid are heavy - really heavy. What's amazing is how much GM has managed to pare off of

the Hybrid's curb weight, as the mass difference between a regular Yukon and this eco model is more than nominal. That's 400 lbs they've managed to strip out, by the way, especially impressive since it still has all the luxuries and goodies, not to mention it's quieter than the standard truck. They've done it by replacing the wheels, which despite being 19 inches across weigh 5 lbs less apiece. The hood's aluminum and the front seats are thinner and lighter. And it's not lighter because they've stripped out 220 lbs worth of insulation either; by switching components like the air conditioner compressor and power steering to electric units, GM has quieted things down significantly.

So does it work? Is the sky blue? I drove the Yukon in a mix of city and highway and obtained a rating of 24 mpg. Admittedly, this meant driving a bit slower than usual, and pretending that an egg was resting just behind the accelerator pedal to ensure the electric motors would be the sole source of power for as long as possible, but driven with a light foot GMC's Hybrid works like a charm. People might seem inclined to honk at stop lights, but when they see the big Hybrid badges across the

side, just like a slow-moving Prius, they seem to be a bit more understanding. They might even smile. When was the last time you saw a Yukon of any sort disarm an irate road-raging person?

I can also say that without question, it's the quietest GMT900-series sport utility vehicle currently on sale, and not just when it's sneaking around on pure electric power. Unlike the various other hybrids on the market, you truly cannot feel the engine starting up and shutting down. Vibrations, even the faintest ones, are AWOL. The only way you're going to see that the six-liter isn't snoozing away is by watching the gauges, looking at the 2 Mode's schematics on the nav screen and listening for the distant thrum of its exhaust system.

There are a couple of things to know about the Yukon, if you intend on towing. After you hitch up your trailer, mobile home or boat using the reverse camera, and head on your way, you won't find a towing mode on the end of the transmission lever. Instead, to get more control out of it, drop the column shifter down to manual mode, where you can cycle through four

forward gears (not to be confused with the four electronically created artificial ratios). Under these conditions the Yukon Hybrid behaves very much like a regular Yukon, with four forward gears. On the highway, cruising at 60 mph, the Yukon's tach reads a little over 1,500 rpm; shift into M4, the manual mode, and it spikes up to 2,200 rpm.

But besides the fact that this is a Hybrid, the electrified Yukon is very much like any other Yukon. It's a big step up into its cabin, and to drive, it feels like a big, easy-going body-on-frame sport utility vehicle. The seats are supremely comfortable, despite being thinner to save weight, and are contoured for the long haul, plus the instruments, aside from the little hybrid-specific "eco" gauges, are straightforward. If you're at home behind the wheel of one of these, there's nothing that separates the Hybrid from one of its standard kin, except the silence of the engine at idle and the ever-present electrical whine from its electrical motors. The distant, siren-like wail often makes you perk up to the potential of the fuzz around you. Crank up the Bose stereo system, though, and it feels normal. The brakes are a bit on the sensitive side, and although Yukons have light steering in general,

the Hybrid's full electric power assisted steering is even more remote and weightless. It, and its surprisingly tight turning circle are handy in town.

And then there's a matter of price, which is where things get even trickier. Big SUV drivers know that fueling a vehicle like a Yukon is gut-wrenchingly, wallet-pinchingly painful, especially if it requires premium fuel, as a Denali does, so is bucking up for the Hybrid worthwhile? I think the answer is pretty clear - yes. Right now, the price of gasoline has never been higher. Oil seems to be hitting a new high on a daily basis, which has resultantly driven up the price of gasoline, and there doesn't seem to be a ceiling in sight. As the price of fuel gets higher, the break even point on one's return on investment begins to move closer and closer to the purchase date, especially given the difference between non-Hybrid and Hybrid versions of the truck.

Where the Yukon Hybrid makes its strongest case is with those in the market for something along the lines of the aforementioned Denali. To recuperate

the cost of the exotic components, GMC has tossed in all the major luxuries as standard equipment - leather, dual-zone climate control, navigation and more. Therefore, if you're comparing comparatively-equipped vehicles, the Denali with navigation is $1,415 more expensive than a base Yukon Hybrid 4WD with nav. However, if all you need is a big SUV that's capable of towing and moving, and you don't care for the goodies, it may be harder to justify the purchase. Still, this is a technology that's going to make a vehicle like the Yukon more socially acceptable, not to mention economically viable to run.

Hybrids may have started out in miserly subcompacts, but they've made their way into heavy Detroit iron. Definitely, it's a change of scenery, but it makes a lot of sense here simply because it makes such a big difference. And seeing as the system will be available in the Sierra (and down the road, on the new Dodge Ram), if you need a green workhorse your ticket will soon be here. Laugh as people may at the fact that this year's Green Car of the Year is a three-ton sport utility vehicle, but it's hard to escape the fact that as a hybrid, it does an admirably good job. It's what I'd call progress.