The new 2007 Chevrolet Tahoe will be available beginning in January with two V8 engines, both displacing 5.3 liters and outputting 320 horsepower and 340 lb.-ft. of torque. Tahoes turning only the rear wheels get the conventional gas-burning version, while 4WD models employ GM’s Flex-Fuel E85 engine that is capable of burning fuel composed of as much as 85-percent ethanol. You don’t have to buy E-85 for the Tahoe 4WD; it runs on pure gasoline or a fuel mixture of up to 85-percent ethanol.

Both engines benefit from Active Fuel Management, a fuel-saving technology that deactivates half of the cylinders under low-load conditions. GM reports that the Tahoe 2WD gets 16-mpg city and 22-mpg highway, with numbers that decrease by one mpg each for 4WD versions. According to Chevy, Active Fuel Management yields up to seven percent improved fuel economy. Jeep uses similar technology called the Multi-Displacement System (MDS) in the all-new, seven-passenger 2006 Commander’s 5.7-liter V8, although Jeep claims its MDS betters fuel economy by up to 20 percent. However, the Commander’s engine is less efficient to start, with mileage estimated at 14-mpg in the city and 19-mpg on the highway. Chevy claims best-in-class fuel economy for the Tahoe, when compared to the Ford Expedition, Nissan Armada, and Toyota Sequoia.

Later in the production year, a 4.8-liter V8 will become the standard engine in the 2007 Chevy Tahoe with 2WD. When the engine arrives towards the third quarter of 2006, power is expected to rate at 290 horses and 290 lb.-ft. of torque. Fuel economy is yet to be determined.

All 2007 Chevrolet Tahoes shift gears through a four-speed automatic transmission, a pity since its siblings, the Cadillac Escalade and GMC Yukon Denali, get a six-speed automatic as standard equipment. By not offering at least five forward gears, as Jeep does in the Commander and Toyota does in the Sequoia, Chevrolet has limited the Tahoe’s flexibility, economy and performance. At least Chevy matches the Ford Expedition’s four-speed unit, and offers a range of axle ratios to make up for the missing cogs. The Tahoe LS 2WD starts with a 3.42:1 rear axle ratio as standard, with an optional 3.73:1 ratio optional. All Tahoe 4WD models may be optioned with 4.10:1 gearing.

When it comes to structural improvements, Chevrolet has made considerable gains in the new Tahoe’s chassis. GM calls this new platform GMT 900, and it will form the basis for its entire range of full-sized SUVs and pickup trucks. For the Tahoe, GM claims a 49-percent increase in torsional stiffness and a five-percent increase in load capacity. Tangible improvement is also seen in the front suspension and steering. A coil-over-shock configuration replaces the old torsion bar setup in front and a power rack-and-pinion steering system trumps the previous recirculating ball mechanism. Car-like handling requires car-like hardware and this arrangement, along with the Tahoe’s wider track and new frame, bring dramatic improvements in terms of ride and handling. Also new are next-generation Bosch antilock brakes with 50-percent stiffer twin calipers. Out back, a five-link rear suspension arrangement mirrors that of the previous model, although the components have been engineered to be stiffer and more robust.

Three distinct suspension systems will be available on the 2007 Chevrolet Tahoe. Most 2WD and 4WD LS and LT models will get GM’s ZW7 Premium-tuned system for general performance. Tahoe LTZ models use the Z55 setup that includes Autoride automatic load-leveling. Finally, an off-road Z71 package, designed for the backcountry and heavy-duty needs, will become optional on 4WD models later this year.