Road Test – Chevy Tahoe Hybrid
Story by Dan Fritter, photos courtesy GM Canada
Last year, I was handed the keys to a then-new Chevrolet Tahoe for a week-long test. I drove it five times.
Because even before gas broke the dollar-per-litre mark, piloting the 5.3L V8-powered Tahoe proved to be an activity my bank account couldn’t survive. Cruising about town in the most relaxed manner I could manage, the onboard computer still spat out a fuel consumption figure of 16.8 litres per hundred kilometres.
So, when the announcement was made that the upcoming Tahoe Hybrid was going to be released into the local press fleet a few months back, I was suitably interested. After all, I loved the Tahoe’s chunk, substantial look, and loved the way its spacious, comfortable, and easy-to-use interior shortened up the miles. But there was a fly in this optimistic ointment, and that fly’s name? The Silverado Hybrid. A half-cooked idea of a few years back, the Silverado Hybrid utilized a 5.3L V8 with auto shut-off and restart ability. However, a laggy restart system meant eager drivers ended up feeding in too much throttle to get the damn thing to move, making the engine start up at 3,000 rpm and thus frying whatever tire the open differential chose to annihilate. And without any electric motor assistance, fuel mileage was, for the most part, the same as a standard Silverado. Would the Tahoe be different?
Oh yes, it would! Climbing aboard for the first time, the first hint that the Tahoe’s new two-mode hybrid system would distinguish itself as an astounding piece of technology came with a quick glance at the press package. The pages upon pages of available options and grandiose advertorial descriptions were eclipsed by a pair of numbers on the back page: 10.5 and 9.8. The truck’s city and highway fuel economy figures (respectively) talked a big game, and promised even less consumption on Vancouver’s crowded streets than one would get from the diminutive Mini Cooper S. Incredulous, I reset the fuel computer and proceeded out of the parking lot for seven days of commuting, gallivanting, and adventure.
A week later, having commuted and gallivanted about town almost excessively, I flipped back through the various on board computer settings to record my average fuel economy. Although higher than the government rating, the 12.2L / 100 km the truck reported left me duly impressed. For comparison’s sake, the last Mini Cooper S I tested reported 13.0L / 100 km. Capable of speeds of up to 48 kilometres per hour on electric power alone, the Tahoe easily copes with stop-and-go traffic, and is probably the least eager to ignite the gasoline engine under moderate throttle application, excepting perhaps Toyota’s Prius.
Entirely encapsulated within the Tahoe’s transmission, GM’s new hybrid system incorporates a very complex and
perplexing “unique assemblage of two 60 kW electric motors, three planetary gearsets and four traditional hydraulic wet clutches.” Manipulated by a computer that clearly has a superior grasp of the transmission’s workings than yours truly, the system can operate as a traditional economy-minded variable ratio gearbox, or it can utilize fixed-ratio first, second, third, and fourth gears when a more robust gearbox is needed. Interestingly, on the highway, GM’s two-mode system often shuts down the dual 60 kW electric motors (or uses them to generate electricity to charge the batteries) and pops the gearbox into the fixed-ratio fourth, which apparently provides superior fuel economy than a traditional hybrid system would allow.
You needn’t know any of this, though, because as far as the occupants are concerned, this is just another, big, comfy couch of a Tahoe. Excepting the strange eco gauge that seemingly bounces about of its own accord, and the drivetrain readout in the nav unit, the Hybrid runs, drives and feels like a standard Tahoe. Sure, it turns itself off on a regular basis, but there’s no laggy restart to cope with, and the engine itself is damped to such a degree that there’s no discernible shake, shimmy, or vibration when it fires the big 6.0L back up. Put your foot into it, and it drops gears and hauls seven derrieres just as well as the standard Tahoe, if not even better. And while you might notice the deeper, more aerodynamic front air dam, chances are your eye would skip over the deleted roof rack cross bars, slightly enlarged grille opening, extended D-pillar appliqués, tapered running boards and wheel spats, and aluminum hood and liftgate. A half-baked hybrid this is not.
Definitely a showpiece for the progress GM has made in just three short years, the Tahoe Hybrid illustrates how serious General Motors is about addressing what is now the biggest concern among new car buyers – fuel consumption. And while it may not have a fancy name, GM’s 2-Mode Hybrid drivetrain system easily bests Honda’s Integrated Motor Assist, and is on par with Toyota’s excellent Hybrid Synergy Drive. Taking one of GM’s most practical vehicles and making it downright sensible to drive, Chevy has successfully vanquished the Tahoe’s single largest detractor. With similar drivetrains now available in the GMC Yukon and Cadillac Escalade, you can expect these fuel-sipping gargantuan SUVs to be blowing minds, and sales figures, all over the country.[PSGallery=ewyttwtvo]
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