R18 PONTIAC GRAND PRIX 2008 Owners Manual

Low-Prole Performance Tire (GXP)
If your vehicle has P255/45R18 size tires on the
front wheels and P225/50R18 size tires on the
rear wheels, they are classied as low-prole
performance tires. These tires are designed for very
responsive driving on wet or dry pavement. You
may also notice more road noise with low-prole
performance tires and that they tend to wear faster.
Notice:If your vehicle has low-prole tires,
they are more susceptible to damage from road
hazards or curb impact than standard prole
tires. Tire and/or wheel assembly damage
can occur when coming into contact with road
hazards like, potholes, or sharp edged
objects, or when sliding into a curb. Your
vehicle warranty does not cover this type of
damage. Keep tires set to the correct ination
pressure and, when possible avoid contact
with curbs, potholes, and other road hazards.
Tire Sidewall Labeling
Useful information about a tire is molded into its
sidewall. The examples below show a typical
passenger vehicle tire and a compact spare tire
sidewall.(A) Tire Size
:The tire size is a combination of
letters and numbers used to dene a particular
tire’s width, height, aspect ratio, construction type,
and service description. See the “Tire Size”
illustration later in this section for more detail.
(B) TPC Spec (Tire Performance Criteria
Specication)
:Original equipment tires designed
to GM’s specic tire performance criteria have a
TPC specication code molded onto the sidewall.
GM’s TPC specications meet or exceed all federal
safety guidelines.Passenger (P-Metric) Tire Example
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You have two minutes to match each tire and wheel
position. If it takes longer than two minutes to match any
tire and wheel position, the matching process stops and
you need to start over.
The TPMS matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to ON/RUN with the
engine off.
3. Press the Remote Keyless Entry (RKE) transmitter’s
LOCK and UNLOCK buttons at the same time for
approximately ve seconds. The horn sounds twice
to signal the receiver is in relearn mode.
4. Start with the driver side front tire.
5. Remove the valve cap from the tire’s valve stem.
Activate the TPMS sensor by increasing or
decreasing the tire’s air pressure for 10 seconds, or
until a horn chirp sounds. The horn chirp, which
may take up to 30 seconds to sound, conrms that
the sensor identication code has been matched to
the tire/wheel position.
6. Proceed to the passenger side front tire, and repeat
the procedure in Step 5.
7. Proceed to the passenger side rear tire, and repeat
the procedure in Step 5.8. Proceed to the driver side rear tire, and repeat the
procedure in Step 5. The horn sounds two times to
indicate the sensor identication code has been
matched to the driver side rear tire, and the TPMS
sensor matching process is no longer active.
9. Turn the ignition switch to LOCK/OFF.
10. Set all four tires to the recommended air pressure
level as indicated on the tire and loading
information label.
11. Put the valve caps back on the valve stems.
Tire Inspection and Rotation
We recommend that you regularly inspect your
vehicle’s tires, including the spare tire, for signs of
wear or damage. SeeWhen It Is Time for New
Tires on page 5-77for more information.
Tire rotation is not recommended if your vehicle is
a GXP model equipped with P255/45R18 size tires
on the front wheels and P225/50R18 size tires on
the rear wheels. Different tire sizes front to rear
should not be rotated.
Tire rotation is recommended if the original
equipment tires installed on your vehicle are of the
same size and type on all four tire/wheel positions.
Original equipment tires of the same size and type
should be rotated every 5,000 to 8,000 miles
(8 000 to 13 000 km). SeeScheduled Maintenance
on page 6-4.
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Tire Chains
{CAUTION:
If your vehicle has P225/55R17, P255/45R18 or
P225/50R18 size tires, do not use tire chains,
there is not enough clearance.
Tire chains used on a vehicle without the
proper amount of clearance can cause damage
to the brakes, suspension or other vehicle
parts. The area damaged by the tire chains
could cause you to lose control of your vehicle
and you or others may be injured in a crash.
Use another type of traction device only if its
manufacturer recommends it for use on your
vehicle and tire size combination and road
conditions. Follow that manufacturer’s
instructions.
CAUTION: (Continued)
CAUTION: (Continued)
To help avoid damage to your vehicle, drive
slowly, readjust or remove the device if it is
contacting your vehicle, and do not spin your
wheels.
If you do nd traction devices that will t,
install them on the front tires.
Notice:If your vehicle does not have P225/55R17,
P255/45R18 or P225/50R18 size tires, use tire chains
only where legal and only when you must. Use only
SAE Class S-type chains that are the proper size for
your tires. Install them on the front tires and tighten
them as tightly as possible with the ends securely
fastened. Drive slowly and follow the chain
manufacturer’s instructions. If you can hear the
chains contacting your vehicle, stop and retighten
them. If the contact continues, slow down until it
stops. Driving too fast or spinning the wheels with
chains on will damage your vehicle.
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