GMC Sierra Power Steering - Quadrasteer

Gimmick? Or Gotta Have It?

Randy Fish Jun 1, 2003 0 Comment(s)
Sucp_0306_01_z Gmc_sierra_power_steering Silverado 1/4

Do you remember the days when most vehicles had, maybe, power steering and no other options to speak of? Fast-forward to 2003, however, and you'll find we're smack dab in the middle of "Bells and Whistles-Ville." Many of us aren't comfortable driving a truck that has radio-delete, crank-up windows, and manual locks. We need power-everything, on-demand four-wheel drive, heated seats, On-Star, and a host of other user-friendly add-ons. Now, we have another technologically advanced option to consider-Quadrasteer. Granted, it's a bit pricey, but is it just a gimmick? Or is it one of those seldom-considered luxuries that we shouldn't quickly strike from the order sheet without the slightest bit of consideration?

With the debut of Quadrasteer on the '02 GMC Sierra Denali, GM's engineering team considered it to be a milestone in full-size truck handling and control. The innovative system consists of an electromechanical unit that turns the rear wheels up to 12 degrees, in relation to the front wheels. This results in, as the factory says, "unprecedented low-speed maneuverability and high-speed stability." Quadrasteer senses the driver's desired steering input with a steering-wheel position sensor.

This information feeds into an on-board microprocessor that determines appropriate rear-wheel angles, based on steering input and vehicle speed. The processor then supplies its data to an electric motor, which, based on algorithms, drives the rear steering rack through a planetary gearset to turn the rear wheels in the proper direction. You'll find the following chart interesting. It spells out the most recent innovations in GM chassis control systems by year and model on which it was introduced.

Sucp_0306_02_z Gmc_sierra_power_steering Disc_brakes 2/4

This Silverado featured (as standard equipment) four-wheel disc brakes, four-wheel ABS with dynamic rear proportioning, and multi-leaf rear springs. As part of its option package, it was equipped with P265/75R16 tires ($240), and included at "No Charge" were a 3.73:1 rear axle ratio, a 6,900-pound GVW rating, and the California emissions package.

Intelligent GM
Chassis Control Systems
1986: Anti-lock braking systems (ABS) introduced on Corvette
1990: Cadillac Allante becomes the first front-wheel-drive vehicle with electronic traction control
1991: All Cadillacs come with standard ABS
1992: GM offers ABS and traction control on more models than any other auto manufacturer
1993: Road Sensing Suspension (RSS) and speed-sensitive steering introduced as part of the Northstar System for the Allante
1995: An Integrated Chassis Control System (ICCS) added to the Northstar System
1996: Continuously Variable Road Sensing Suspension (CV-RSS) and Magnasteer debuted on Cadillac models
1997: StabiliTrak introduced on three Cadillac models-Seville Touring Sedan, Eldorado Touring Coupe and DeVille Concours
1998: Corvette's Active Handling introduced
2000: StabiliTrak 2.0 introduced on DeVille, adding side-slip rate control and active steering effort compensation
2000: Four-channel Precision Control System introduced on Oldsmobile Intrigue, bringing stability enhancement advantages to a family sedan
2000: Traction Control introduced on full-size sport-utilities
2001: Second-generation Active Handling introduced on Corvette
2002: Cadillac STS receives Magnetic Ride Control, the world's fastest-reacting suspension
2002: Quadrasteer debuts on GMC Sierra Denali
2003: Magnetic Selective Ride Control debuts on Corvette

We decided to find out what this engineering marvel is all about. The mule vehicle came from the GM Communications Media Fleet, handsomely equipped, eager to spoil us, and set to prove a thing or two. This '03 Silverado LT 1500 four-wheel drive, extended-cab pickup carried a standard price of $34,278. As tested, it topped out at $41,318. And while the Quadrasteer package added $5,715 to the mix, the total list of options on this beauty reached $6,295. Jeez, it had dual-zone automatic air conditioning, AM/FM stereo with an in-dash six-CD changer, XM Satellite Radio, Bose speakers, six-way (heated) front bucket seats with memory, a leather-wrapped steering wheel with thumb-touch, horn-pad mounted cruise and radio controls, and the list goes on. The Quadrasteer option consisted of (among other items) the heavy-duty trailering package, limited-slip differential, and a 145-amp alternator.

Sucp_0306_04_z Gmc_sierra_power_steering Quadrasteer_system 3/4

The innovative Quadrasteer system consists of an electromechanical unit that turns the rear wheels up to 12 degrees, in relation to the front wheels. It senses the driver's desired steering input with a steering-wheel position sensor. This information feeds into an on-board microprocessor that determines appropriate rear-wheel angles, based on steering input and vehicle speed. The processor then supplies its data to an electric motor, which, based on algorithms, drives the rear steering rack through a planetary gearset to turn the rear wheels in the proper direction.

In order to really determine if Quadrasteer is a "Gimmick or a Gotta Have It," our pal Jerry Murray cordially loaned us his nicely equipped 24-foot trailer. And although it's been a while since yours truly has spent a bunch of time in the cab, a great deal of my past life was spent behind the wheel of a crew-cab dualie towing a 40-foot, triple-axle trailer to NSRA and Goodguys events. Oh, how the nightmares come back!

Riding solo (without the trailer) to start with, my first impression was tentative. The Quadrasteer offered somewhat of a "crab-walk" feeling, but that went away in no time. And being based in Southern California, we have lots of show-offs driving lifted, tricked-out 4x4s, so it was cool being able to upstage them all, as I drove this four-steer road warrior. At freeway speeds, lane changes were effortless, smooth, and calculated, and maneuvering in town, turning at intersections and into parking lots, Quadrasteer is a system you'd quickly come to appreciate.

However, since its intended purpose is to enhance maneuverability while towing, it was time to hook up. The trailer in question came well equipped, so we attached its full complement of load-equalizer bars and headed down the freeway. The old trailer I formerly towed was almost twice as long, and sported a fifth-wheel hookup, which yields totally different characteristics as compared to a tag-along. Nonetheless, it got me in the habit of making wide turns for proper clearance and tracking.

This time, however, the 24-foot tag-along trailer became all but non-existent as I navigated much sharper turns for freeway on-ramps and continued with quick, at-speed lane changes and general highway cruising. Those wide, sweeping turns I was accustomed to negotiating became a thing of the past as the rear wheels were now helping the entire package (truck and trailer) become much more "turning efficient" while loaded and under power. I can easily understand how the Quadrasteer option could turn a "non-towing" driver into a seasoned veteran with a small amount of practice. And no, it doesn't instill a false sense of security; it helps your trailer follow a more positive and predictable track-just like your old dog, Duke, does when he's hungry.

But, is Quadrasteer merely a new-fangled gimmick? Or is it one of those "Gotta have it" engineering marvels that you can't live without? Well, let's just say it's a purpose-built system that displays its inherent benefits in a short amount of time. For those who tow frequently in congested areas, or business owners whose needs warrant it, Quadrasteer would certainly be easy to get used to.

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