At low speed,
the rear wheels turn in the opposite direction of the front to help the
truck maneuver into tight spots. The maximum rear-wheel turning angle
is 12 degrees. At high speeds, the rear wheels turn in the same direction
of the front wheels. This action reduces vehicle yaw and lateral forces
during sudden lane changes because the rear wheels aren’t being
dragged by the front of the vehicle.
Vehicles equipped with Quadrasteer can be operated in normal front-steer
only, 4-wheel steer or a special 4-wheel-steer tow mode. The driver makes
the selection using a push-button switch on the dashboard. The special
tow mode increases the rear steering angle at higher speeds for additional
control.
The $1995 Quadrasteer option includes the following equipment required
for operation:
• Redesigned pickup bed with flared fenders
• Heavy-duty front and rear disc brakes
• ZX3 Ride Control Suspension Package
• 145-amp alternator
• Heavy-duty limited slip differential
• Traction control
• Cab market lights
The massive Stepside-styled rear flares accommodate the extra five inches
of track width and clear the additional steering angle. By law, the wider
rear end requires roof, side and tail marker lights to signify the increased
vehicle width. The rotors on the rear disc brakes grow from 12.8x0.78
to 13.0x1.18 on Quadrasteer 1500 vehicles. The ZX3 suspension includes
driver selectable shock damping to adjust for different road conditions
or ride comfort.
Electric
steering may terrify traditional drivers. Trusting a vehicle’s directional
movements to a computer, electric motor and planetary steering rack can
be unnerving—regardless of the speed. But Delphi officials stress
that Quadrasteer has completed rigorous testing. The company wouldn’t
elaborate on backup systems designed to assure drivers that the rear wheels
won’t steer on their own or lock to one side during an electrical
malfunction or power loss. Officials simply said if the system fails,
Quadrasteer provides a controlled return to two-wheel steering. Besides,
Chevy drivers already trust the throttle operation to a computer. Why
not the steering?
From a maintenance perspective, Quadrasteer doesn’t impose any
undue demands on the owner. Delphi says Quadrasteer has neither a positive
or negative impact on tire wear. Quadrasteer vehicles can become misaligned
in the rear, but officials say chances are less than in the front. There
is no sensing device to alert the driver if the rear is out of alignment.
The driver typically becomes aware of misalignment when the steering wheel
is off center. Those who go off-roading on severe trails may risk getting
some mechanicals caught on a rock or thick brush, but otherwise the system
should not impede any other driving activities.
Our LT-trimmed Silverado drove as cushy and comfortable as any top-of-the-line
pickup. We’ll detail the LT driving experience more in an upcoming
story on a 2004 Silverado LT 1500 Crew Cab 4x4 that we tested shortly
after the drive in the Quadrasteer truck. For the record, we recorded
12 mpg during one week of steady short-hop trips around the beach community.
Our LT had a base price of $32,235 and an as-tested price of $35,065.
Beside Quadrasteer, the truck’s other options included heavy-duty
trailering package, XM radio, traction control and a tire upgrade.
Quadrasteer’s
advantages far outweigh any disadvantages, and the new price point makes
worthy of consideration when purchasing a Chevy Extended Cab or Crew Cab
truck. This innovation will surely find its way into more trucks. Future
applications could include developing electronic front steering and interfacing
the front and rear wheels with the brakes to automatically regain control
in uncertain circumstances. For now, we’d just like a little program
in the computer that will allow us to crab-crawl at low speeds to make
grand entrance at the Friday night cruise or angle into a parallel parking
spot without backing up.
