What could make a pick up truck worth more than $40,000? A 16-cylinder diesel engine? An "unborn" Naugahyde interior? Fenders made of polished stainless steel? Nope. The correct answer is…Quadrasteer, a hot new feature on the 2002 GMC Sierra Denali. Introduced last year as the C3 but substantially upgraded, the Sierra Denali has plenty of traction thanks to its husky 300-hp, 6.0-liter Vortec V-8 and full-time four-wheel-drive system. The interior is suitably luxurious with soft leather upholstery and woodgrain trim. But what really separates the Denali from the pack is its four-wheel steering system, which represents a quantum leap in maneuverability and stability, particularly while towing.
I hitched the truck to a 26' Cobalt on its tandem-axle trailer and drove my southeastern Michigan test course, which consists of busy freeways, desolate back roads, and one handy Department of Natural Resources launch ramp. Although the 5,840-pound payload topped the Denali's curb weight by a couple hundred pounds, it was only 60 percent of the truck's towing capacity.
The four-wheel steering system has a computer that commands an electrically powered steering gear on the truck's rear axle. At low speeds, it cocks up the rear wheels as much as 12 degrees to chop the turn circle from a cumbersome 47.3' to a tidy, car-like 37.4'. As a comparison, the Honda Accord requires 36.4' to make a U-turn. At higher speeds, the computer steers the rear wheels in phase with the front wheels to prevent the truck's tail from wagging.
The benefits were immediately obvious. While backing the trailer down the ramp, the Denali reacted to my steering at least twice as fast as a conventional chassis. As I turned the wheel, the trailer angled obediently into position-no waiting, no wandering, no wondering.
A switch on the dash lets you change from normal Quadrasteer to a towing mode. During the test, I sawed the wheel injudiciously to and fro, yet the truck and trailer glided from lane to lane with the smooth assurance of a pro slalom skier. My opinion? Four-wheel steering is a godsend; the sooner it's installed on all tow trucks, the better.
The Quadrasteer system does have a couple of drawbacks, though. It weighs 400 pounds and the system needs space. The rear of the Denali is so wide that it requires roof and fender-mounted clearance lamps. Be careful at the car wash.
The Denali's Vortec V-8 has all the guts you'll need for big towing jobs, and there's a convenient transmission temperature gauge, too. Even without a low range in its transfer case, this truck had all the torque and surefooted traction it needs to haul any large, heavy boat from your lake's wet grasp.
|MODEL||GMC SIERRA DENALI|
|Engine||6.0-liter OHV V-8|
|Net torque (ft-lb/rpm)||360/4000|
|Suspension Front||control arms, torsion bars|
|Suspension Rear||rigid axle, semi-elliptic leaf springs|
|Brakes (front/rear)||disc/disc 4-wheel ABS|
|Tires||Michelin CrossTerrain, P265/70SR-17 all terrain|
|Curb weight (lbs.)||5,660|
|Towing capacity (lbs.)||10,000|
|Cargo capacity (max. cu. ft.)||57|
|Fuel capacity (gal.)||26|
|City/highway towing fuel economy (avg. mpg)||8.0|
LAST WORD. The Sierra Denali's Quadrasteer is a great innovation and a real boon to towing.