2006 PONTIAC GRAND PRIX wheel size

When It Is Time for New Tires.......................5-71
Buying New Tires.........................................5-72
Different Size Tires and Wheels......................5-73
Uniform Tire Quality Grading..........................5-74
Wheel Alignment and Tire Balance..................5-75
Wheel Replacement......................................5-75
Tire Chains..................................................5-77
If a Tire Goes Flat........................................5-77
Tire Inator Kit (GXP)....................................5-79
Changing a Flat Tire.....................................5-88
Removing the Spare Tire and Tools................5-90
Removing the Flat Tire and Installing
the Spare Tire..........................................5-91
Storing a Flat or Spare Tire and Tools............5-97
Compact Spare Tire......................................5-99
Appearance Care............................................5-99
Cleaning the Inside of Your Vehicle.................5-99
Fabric/Carpet..............................................5-101
Leather......................................................5-103
Ultra Lux Suede..........................................5-103
Instrument Panel, Vinyl, and Other
Plastic Surfaces.......................................5-104
Care of Safety Belts....................................5-104
Weatherstrips.............................................5-104Washing Your Vehicle..................................5-105
Cleaning Exterior Lamps/Lenses....................5-105
Finish Care................................................5-105
Windshield and Wiper Blades.......................5-106
Aluminum Wheels.......................................5-106
Tires.........................................................5-107
Sheet Metal Damage...................................5-107
Finish Damage...........................................5-107
Underbody Maintenance...............................5-108
Chemical Paint Spotting...............................5-108
Vehicle Care/Appearance Materials................5-109
Vehicle Identication.....................................5-110
Vehicle Identication Number (VIN)................5-110
Service Parts Identication Label...................5-110
Electrical System..........................................5-111
Add-On Electrical Equipment.........................5-111
Headlamp Wiring........................................5-111
Windshield Wiper Fuses...............................5-111
Power Windows and Other Power Options......5-111
Fuses and Circuit Breakers..........................5-112
Instrument Panel Fuse Block........................5-112
Underhood Fuse Block................................5-114
Capacities and Specications........................5-118
Section 5 Service and Appearance Care
5-2

{CAUTION:
Poorly maintained and improperly used tires
are dangerous.
Overloading your tires can cause
overheating as a result of too much
friction. You could have an air-out and a
serious accident. SeeLoading Your
Vehicle on page 4-33.
Underinated tires pose the same
danger as overloaded tires. The resulting
accident could cause serious injury. Check
all tires frequently to maintain the
recommended pressure. Tire pressure
should be checked when your tires are
cold. SeeInflation - Tire Pressure on
page 5-67.
Overinated tires are more likely to be cut,
punctured, or broken by a sudden
impact — such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn, old tires can cause accidents. If
your tread is badly worn, or if your tires
have been damaged, replace them.
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 GM 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.
5-61

Tire Size
The following illustration shows an example of a typical
passenger vehicle tire size.
(A) Passenger (P-Metric) Tire:The United States
version of a metric tire sizing system. The letter P as the
rst character in the tire size means a passenger
vehicle tire engineered to standards set by the U.S. Tire
and Rim Association.
(B) Tire Width:The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.
(C) Aspect Ratio:A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is 60, as shown in item C of
the illustration, it would mean that the tire’s sidewall is
60 percent as high as it is wide.(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire. The
letter R means radial ply construction; the letter D means
diagonal or bias ply construction; and the letter B means
belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:These characters represent
the load range and speed rating of the tire. The load
index represents the load carry capacity a tire is certied
to carry. The load index can range from 1 to 279. The
speed rating is the maximum speed a tire is certied
to carry a load. Speed ratings range from A to Z.
Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire’s height to
its width.
5-64

Tire Inspection and Rotation
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).
Any time you notice unusual wear, rotate your vehicle’s
tires as soon as possible and check the wheel
alignment. Also check for damaged tires or wheels. See
When It Is Time for New Tires on page 5-71and
Wheel Replacement on page 5-75for more information.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The rst rotation
is the most important. SeeScheduled Maintenance
on page 6-4for scheduled rotation intervals.The correct rotation pattern shown here is only for
non-GXP tires.
Do not include the compact spare tire, if equipped, in
your vehicle’s tire rotation.
After the tires have been rotated, adjust the front and
rear ination pressures as shown on the Tire and
Loading Information label, and reset the Tire Ination
Monitor System. SeeTire Ination Monitor System
on page 5-68for additional information. Rotation Pattern for Non-GXP Tires Only
5-70

Make certain that all wheel nuts are properly tightened.
See “Wheel Nut Torque” underCapacities and
Specications on page 5-118.
{CAUTION:
Rust or dirt on a wheel, or on the parts to
which it is fastened, can make wheel nuts
become loose after a time. The wheel could
come off and cause an accident. When you
change a wheel, remove any rust or dirt from
places where the wheel attaches to the vehicle.
In an emergency, you can use a cloth or a
paper towel to do this; but be sure to use a
scraper or wire brush later, if needed, to get all
the rust or dirt off. SeeChanging a Flat Tire on
page 5-88.
When It Is Time for New Tires
One way to tell when it is
time for new tires is to
check the treadwear
indicators, which will
appear when your tires
have only 1/16 inch
(1.6 mm) or less of tread
remaining.
You need a new tire if any of the following statements
are true:
You can see the indicators at three or more places
around the tire.
You can see cord or fabric showing through the
tire’s rubber.
The tread or sidewall is cracked, cut, or snagged
deep enough to show cord or fabric.
The tire has a bump, bulge, or split.
The tire has a puncture, cut or other damage that
cannot be repaired well because of the size or
location of the damage.
5-71

Buying New Tires
GM has developed and matched specic tires for your
vehicle. The original equipment tires installed on
your vehicle, when it was new, were designed to meet
General Motors Tire Performance Criteria Specication
(TPC spec) system rating. If you need replacement
tires, GM strongly recommends that you get tires with
the same TPC Spec rating. This way, your vehicle
will continue to have tires that are designed to give the
same performance and vehicle safety, during normal
use, as the original tires.
GM’s exclusive TPC Spec system considers over a
dozen critical specications that impact the overall
performance of your vehicle, including brake system
performance, ride and handling, traction control, and tire
pressure monitoring performance. GM’s TPC Spec
number is molded onto the tire’s sidewall by the
tire manufacturer. If the tires have an all-season tread
design, the TPC spec number will be followed by an MS
for mud and snow. SeeTire Sidewall Labeling on
page 5-62for additional information.{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
(other than those originally installed on your
vehicle), brands, or types (radial and
bias-belted tires), the vehicle may not handle
properly, and you could have a crash. Using
tires of different sizes (other than those
originally installed on your vehicle) may also
cause damage to your vehicle. Be sure to use
the correct size, brand, and type tires on all
wheels. If your vehicle has a compact spare
tire, it is all right to drive your vehicle with the
compact spare temporarily. It was developed
for use on your vehicle. SeeCompact Spare
Tire on page 5-99.
5-72

{CAUTION:
If you use bias-ply tires on your vehicle, the
wheel rim anges could develop cracks after
many miles of driving. A tire and/or wheel
could fail suddenly, causing a crash. Use only
radial-ply tires with the wheels on your vehicle.
If you must replace your vehicle’s tires with those that
do not have a TPC Spec number, make sure they
are the same size, load range, speed rating, and
construction type (radial and bias-belted tires) as your
vehicle’s original tires.
Your vehicle’s original equipment tires are listed on the
Tire and Loading Information Label. This label is
attached to the vehicle’s center pillar (B-pillar). See
Loading Your Vehicle on page 4-33, for more information
about the Tire and Loading Information Label and its
location on your vehicle.
Different Size Tires and Wheels
If you add wheels or tires that are a different size than
your original equipment wheels and tires, this may
affect the way your vehicle performs, including its
braking, ride and handling characteristics, stability and
resistance to rollover. Additionally, if your vehicle
has electronic systems such as, antilock brakes; traction
control; and electronic stability control, the performance
of these systems can be affected.
{CAUTION:
If you add different sized wheels, your vehicle
may not provide an acceptable level of
performance and safety if tires not
recommended for those wheels are selected.
You may increase the chance that you will
crash and suffer serious injury. Only use GM
specic wheel and tire systems developed for
your vehicle, and have them properly installed
by a GM certied technician.
SeeBuying New Tires on page 5-72andAccessories
and Modications on page 5-3for additional information.
5-73

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. 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.
If a Tire Goes Flat
It is unusual for a tire to blowout while you are driving,
especially if you maintain your tires properly. See
Tires on page 5-60. If air goes out of a tire, it is much
more likely to leak out slowly. But if you should ever
have a blowout, here are a few tips about what to expect
and what to do:
If a front tire fails, the at tire will create a drag that
pulls the vehicle toward that side. Take your foot off the
accelerator pedal and grip the steering wheel rmly.
Steer to maintain lane position, and then gently brake to
a stop well out of the traffic lane.
5-77