Turning to Technology
Four-wheel steering comes of age.
When it comes to hunting and fishing, bigger is better. That’s why so many outdoorsmen opt for big trucks. Giant SUVs, such as the Chevy Suburban, and the new wave of 1/2-ton crew-cab pickups offer plenty of room for hunting buddies and all their gear. Add a trailer to the picture and you just can’t beat full-size trucks for their Gibraltar-like stability on the highway.
There is a trade-off, however, for all this roadworthy real estate. The longer wheelbase of a bigger truck means reduced maneuverability.
Fortunately, technology has an answer in the form of four-wheel steering: By turning the rear wheels in the opposite direction of the front wheels, a full-size pickup can turn around in a much smaller area. That’s important when you need to change directions on an earthen dam. Maneuverability is even more critical when towing a bass boat or trailer.
General Motors is now offering four-wheel steering on a growing number of full-size pickups and SUVs. Called Quadrasteer, the electromechanical system turns the rear wheels in relation to the front wheels for increased low-speed maneuverability and enhanced high-speed stability.
**How Quadrasteer Works **
An electrically powered rear-wheel steering system senses vehicle speed and steering input to determine how much to turn the rear wheels and in which direction. GM designed the system around a heavy-duty rear axle, which offers the benefit of high tow ratings. Fitting the system requires widening the rear track (the distance between the rear wheels) by 5 inches, but the increased width is more than offset by improved offroad maneuverability.
At low speeds, Quadrasteer turns the rear wheels up to 12 degrees in the opposite direction as the front wheels. At high speeds, it turns the rear wheels slightly in the direction of the front wheels. It sounds like a high-speed shopping cart, but it works great. Quadrasteer also reduces the turning diameter of a full-size truck by more than 20 percent, and that means a substantial improvement in vehicle maneuverability on trails with hairpin turns, steep dropoffs, and narrow cuts.
Moving a trailer around a campsite or a boat down a launch ramp is now a whole lot easier because the rig takes less space to turn and the trailer responds better and more intuitively to steering input, reducing the usual left and right gyrations. At highway speeds, Quadrasteer lessens the effects of crosswinds and passing tractor-trailers. Truck and trailer move down the highway as if they were one, and fewer corrections are required after making a quick lane change.
The system can take a little getting used to, but you’ll quickly appreciate the improved parallel parking capability. It can be switched off by pressing a 4WS button that returns it to the two-wheel steer mode. In case you were wondering, it reverts to normal two-wheel steering if a system failure is detected. Only a small percentage of GM’s trucks will be equipped with Quadrasteer for the 2003 model year: Chevrolet Suburban and GMC Yukon XL 2500-series models, and Chevrolet Silverado and GMC Sierra 1500HD Crew Cabs. It was introduced on the 2002 Sierra Denali luxury pickup and was recently added to GM’s extended-cab short-box pickups.
Quadrasteer is not offered as a stand-alone option on all models. On Silverados, for example, the package retails from $5,700 to $7,500, but includes other appealing features: the popular Vortec 5300 V-8, heavy-duty trailering equipment, 3.73 axle ratio, limited-slip rear differential, adjustable suspension damping, 130-amp alternator, and roof marker lamps.
Four-wheel steering is a useful bit of technology for the outdoorsman. If you’re thinking about getting a new truck and you spend a lot of time offroad or towing a trailer, you’d be crazy not to check it out.