When General Motors first announced its plans to launch hybrid models of its popular pickup truck and SUV lineup, critics clamored that such a big hybrid was a waste of technology. In reality, getting a small car to average 45 miles per gallon shouldn't be all that hard, but getting a massive SUV weighing in at just under three tons to average over 20 mpg is very impressive.
That is just what GM has accomplished in launching hybrid models of the Chevrolet Tahoe and GMC Yukon (with Cadillac Escalade, Chevrolet Silverado and GMC Sierra models to follow later this year). When it comes to "green cars," GM is the leading manufacturer of hybrid models.
GMC added the two-mode hybrid model to a Yukon lineup that now boasts four distinct models - the base Yukon, Yukon XL, Yukon Denali and Yukon Hybrid. The 2008 GMC Yukon Hybrid uses technology shared with BMW and the former DaimlerChrysler along with a more efficient, yet still powerful, engine to improve EPA fuel economy estimates to 21 mpg city and 22 mpg on the highway for two-wheel drive models (20 city/20 highway on four-wheel drive models).
The Yukon's Two-Mode Hybrid system combines a 300-volt nickel-metal hydride battery pack with a unique four-speed automatic transmission that incorporates two electric motors. One impressive aspect of the Yukon Hybrid is its ability to go up to 30 mph on electric power only, although acceleration has to be slow and steady. Still there is something eerie and awe inspiring of a vehicle this big rolling around at neighborhood speeds emitting no pollutants and a quiet, high-pitched whine from the motors. Even the Yukon Hybrid's tires are specifically designed with quiet-tuned tread and provide low-rolling resistance.
When coming to an idle either at a stop light or in a parking lot, the engine shuts off and the Yukon Hybrid goes into Auto Mode. Even with the engine not running, the A/C system, power steering and brakes all work as would be expected.
The other impressive aspect of the hybrid system is, of course, the fuel economy gains. After being informed that I would have two weeks behind the wheel of the Yukon Hybrid, I decided to spend the first week dedicated to getting the best possible mileage by altering my driving style to include taking off slowly from lights to keep the electric motors engaged and the engine off for as long as possible. This resulted in an astonishing 23.3 mpg - ALL in the city. The second week, I drove at my normal pace and still managed a respectable 21.4 mpg in mixed driving.
Similar to the other Tahoe and Yukon vehicles, large blind spots exist despite the relatively large side mirrors. With all the technology this vehicle has, a simple blind spot detection device would be extremely useful.
The advanced technology of the two-mode hybrid system is probably the biggest factor in the 50-percent city mileage improvement, but the slight gain in highway fuel economy (up 15 percent) is due more to the unique aerodynamics and the engine's Active Fuel Management system.
Visually, there is no mistaking the Yukon Hybrid for a base Yukon. Besides the numerous stickers and badges announcing it as a hybrid (which there are eight of), the Yukon Hybrid also gets unique body panels that help reduce drag and weight. Up front, the redesigned fascia features a lower air dam and is devoid of fog lights and tow hooks, which help to make the leading edge smoother. Also, the grille opening is taller to improve air flow to the radiator and engine compartment.
Helping to make the already handsome design of the Yukon look and act slicker, the roof racks have been eliminated and the rear end received aerodynamic improvements such as a revised rear fascia, a deeper roof spoiler with built-in LED stop light and aerodynamically shaped D-pillar appliquÃ©s and LED taillights. Finally, to help compensate for the additional weight of the hybrid system, the Yukon Hybrid features extensive use of aluminum such as the hood and liftgate.
Inside, there is little to differentiate the Yukon Hybrid from the regular Yukon's already ergonomic and useful interior. The main differences for the Yukon Hybrid are limited to the instrument cluster, front seats and, of course, the 300-volt battery pack unobtrusively perched beneath the second-row seats.
The cluster, it allows the driver scroll through various screens to view what mode the engine is in and what type of fuel economy the Yukon Hybrid is getting. Additionally, the driver can easily see what mode the engine and hybrid system are in by either the instant economy screen or the navigation system. The information screen is built into the tachometer and shows instant fuel economy and what mode the engine is in. The standard 6.5-inch touch-screen navigation system doubles as a monitor to show the driver what mode the hybrid system is in as well as whether the vehicle is in Auto Mode.
Legroom and headroom for front and second-row passengers is generous. GMC used different front seats that help to reduce mass and decrease overall vehicle weight but has no effect on comfort. Actually, the thinner front seats increases legroom for the second-row seat by 1.5 inches.
Due to the solid rear axle and tried-and-true suspension system, the floor pan of the Yukon is not equipped to allow the third-row seats to offer stadium-style seating or to fold flat. While the seats aren't difficult to remove, they are moderately heavy and are a nuisance when compared to the Ford Expedition's electric fold-flat seats. With only 25.4 inches of rear legroom, taller passengers may want to avoid the third row. One benefit of sitting in the third row is the proximity to a standard household electrical outlet.
As expected from a large SUV, the Yukon Hybrid comes with a powerful 6.0-liter V-8 putting out 322 horsepower and 367 lb-ft of torque. Helping to maximize efficiency, the engine also features GM's Active Fuel Management system, which operates the engine as a V-4 when the vehicle reaches cruising speeds. The transition between the V-4 and V-8 modes is slightly noticeable feeling similar to a late, harsh shift. When coming to stops, the operation of the electric motors and regenerative braking make the Yukon Hybrid sound something like R2-D2.
Cargo capacity for the Yukon Hybrid is identical to the other Yukon models. With the rear seats removed and the second row folded forward, the Yukon can swallow up to 108.9 cubic feet. Towing capacity is affected however dropping from 7,500 pounds (in Yukon 2WD) to 6,200 (in Yukon Hybrid 2WD).
Base MSRP for the two-wheel drive 2008 Yukon Hybrid is $50,045 - a $13,800 premium. As expected from a vehicle in this price range, the Yukon Hybrid comes standard with a laundry list of luxury and convenience features.
For returning GM customers looking to get into one of the new Tahoe or Yukon hybrid models, now is the time. GM is offering a $4,000 cash rebate until June 30, 2008 to current 1999 and newer GM vehicle owners and lessees.