2008 Chevrolet Tahoe Hybrid
- by Jim Prueter - 01/08
Popular Tahoe gets a hybrid
With the industry’s first application of hybrid technology in a full-size SUV, General Motors and Chevrolet break new ground in a category previously dominated by subcompact vehicles like the Toyota Prius and Honda Civic hybrid.
With EPA fuel economy ratings of 21 mpg (city) and 22 mpg (highway) for two-wheel drive hybrids, fuel economy for the Tahoe increases by almost 50 percent in town and 25 to 30 percent in combined city-highway driving, while it maintains a 6,000 pound towing capacity. That’s just 200 pounds less than the non-hybrid Tahoe powered by a standard 5.3-liter V-8.
What really surprised me, however, is the fact that Tahoe’s city fuel economy number matches that of the much-smaller 2008 Toyota Camry sedan, equipped with the 2.4-liter 4-cylinder engine. It gets better mileage than the V-6 Honda Accord and Ford Fusion.
Combined fuel economy for four-wheel drive Tahoe models is rated at 20 mpg in both city and highway driving. The standard 5.3-liter V8 Tahoe models are rated at 14/19 (city/highway).
It’s all made possible by what GM terms the “two-mode” hybrid system, which teams a 6.0-liter V8 gasoline engine with electric motors. The 332 Horsepower V8 engine is linked to two motors and a planetary gear transmission capable of manual-shift mode.
The V-8 saves fuel by shutting down four of its eight cylinders under light driving. One of the electric motor helps to drive the vehicle, allowing it to remain in the economical V-4 mode for longer periods, while the other synchronizes the transmission with the power flow from the V8 engine and the other motor.
When more power is demanded, the system reverts to full capacity, whereas at a stoplight, the gasoline engine shuts off altogether. The electric motor launches the Tahoe from stops and can power the vehicle to 30 mph. It is even equipped to cruise two miles on battery power alone.
The 300-volt nickel-metal hydride battery pack, located under the second-row seats, is recharged by regenerative (regen) braking. The batteries recharge under braking or as the vehicle is slowing. The “hybrid” screen on the dash illustrates the action.
I tested the new Tahoe Hybrid, which goes on sale later this month. It drew the attention of motorists everywhere I drove. Not a difficult task considering Chevy has emblazoned large “Hybrid” decals across both the front and rear windshield and the doors on either side of the vehicle. Additional badging is found on the B pillar, both front fenders and rear liftgate. In total, hybrid is proclaimed in nine different areas.
To help the hybrid system improve mileage, Chevy set the Tahoe about a half-inch lower than the standard model, added a lightweight hood and tailgate, and reshaped the running boards and rear-end treatment. These changes lower the vehicle’s drag co efficiency.
Inside, the front seats are reconfigured to weigh less. They’re 1.6 inches thinner. New features include an “economy” gauge in the instrument panel that coaxes drivers to keep the needle at the twelve o’clock position for optimum mileage. Another gauge indicates if the engine is running on the deactivated four-cylinder mode or full V8 mode. There’s also a “hybrid” choice on the navigation screen that indicates through a live read-out whether the Tahoe is operating on gas, battery or a combination of the two.
I thought the new Tahoe was terrific when I first tested it over a year ago, rating it eight out of 10. The hybrid version eliminates many negatives of on the original issue: poor mileage and a poor transmission. It seems others agree; the hybrid Tahoe was recently awarded Green Car Journal’s “Green Vehicle of the Year”.
The 2WD hybrid Tahoe starts at $50,490 compared to the non-hybrid Tahoe at $34,995, a $15,000 premium for an extra seven miles per gallon. However, the hybrid does include other extras — leather seats, navigation system, back-up camera and running boards— making it difficult to determine the actual cost of the hybrid system alone. The 4X4 hybrid starts at $54,295.
Other hybrids typically cost an additional $2,000 to $3,000 over similar gasoline-only models. GM won’t specifically assign a price tag to the hybrid system, however — as far as we can figure— the fuel-cost savings isn’t going to cover it. We estimated that most drivers could save about $500 per year in combined city-highway driving, assuming 15,000 annual miles at $3 a gallon. Of course, any government tax credit for buying a GM hybrid would help offset the added cost.
If you prefer to drive a GMC, the Yukon hybrid — virtually identical to the Tahoe —launches simulataneously. It will cost an additional $500 model for model. Cadillac will introduce an Escalade hybrid and Chevrolet a Silverado truck hybrid as 2009 models.
Both will launch in the fall of 2008, using the same technology as the Tahoe.
