Four-wheel Steering Finds its Home

GMC's Sierra Denali performance truck, formerly Sierra C3, will head into production this fall offering an innovative standard feature: 4-wheel steering. Although the idea hardly is new for passenger cars (several automakers have tried, without success, to feature 4-wheel steering as a performance-handling enhancement), GMC's application is a world-first for the light-truck segment.

Called Quadrasteer by supplier Delphi Automotive Systems (see WAW — April, '00, p.63), GMC claims it reduces Sierra Denali's turning circle diameter to 37.4 ft. (11.4 m), nearly equal to a compact Saturn coupe's 37.1 ft. (11.3 m). Quadrasteer offers three driving modes available with the press of a button: 2-wheel steer, 4-wheel steering and 4WS tow for pulling a trailer. Most drivers are likely to find the parking-lot maneuverability the most startling advance of Quadrasteer, but those who do a lot of trailering will want to kiss every GMC/Delphi engineer they can find once they get a shot at backing up a rig or towing it in heavy winds with the aid of 4-wheel steering.

Due to Quadrasteer, Sierra Denali also features some chassis upgrades, including a gross-vehicle weight rating increased by 250 lbs. (113 kg) to 4,000 lbs. (1,814 kg) and driver-selectable suspension. Word to the wise: carefully select car washes. Quadrasteer increases Sierra Denali's rear track by 5 ins., and some car wash conveyor tracks may be too small.

Lynn Meyers, Pontiac-GMC marketing general manager, says Quadrasteer might help boost Sierra Denali sales from around 10,000 units to 15,000 annually. “But it was never intended to be a high-volume vehicle,” Ms. Meyers says. “Then, of course, Quadrasteer will begin to roll out across the other Sierra models at some point down the road. It will go optional on the rest of the Sierra lineup.”

At press time, the automaker wasn't disclosing what the Quadrasteer option will cost — or a take rate forecast — once it's available in other trucks besides the Sierra Denali.