2006 PONTIAC GRAND PRIX tire size

Tire and Loading Information Label
A vehicle specic Tire and Loading Information label is
attached to the vehicle’s center pillar (B-pillar). With
the driver’s door open, you will nd the label attached
below the door lock post (striker). The tire and
loading information label lists the number of occupant
seating positions (A), and the maximum vehicle capacity
weight (B) in kilograms and pounds.The Tire and Loading Information label also lists the tire
size of the original equipment tires (C) and the
recommended cold tire ination pressures (D). For more
information on tires and ination, seeTires on
page 5-60andInation - Tire Pressure on page 5-67.
There is also important loading information on the
Certication label. It tells you the Gross Vehicle Weight
Rating (GVWR) and the Gross Axle Weight Rating
(GAWR) for the front and rear axle, see “Certication
Label” later in this section.
Steps for Determining Correct Load Limit
1. Locate the statement “The combined weight
of occupants and cargo should never exceed
XXX kg or XXX lbs” on your vehicle’s placard.
2. Determine the combined weight of the driver and
passengers that will be riding in your vehicle.
3. Subtract the combined weight of the driver and
passengers from XXX kg or XXX lbs. Label Example
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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 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.
(C) DOT (Department of Transportation):The
Department of Transportation (DOT) code indicates that
the tire is in compliance with the U.S. Department of
Transportation Motor Vehicle Safety Standards.
(D) Tire Identication Number (TIN):The letters and
numbers following DOT (Department of Transportation)
code is the Tire Identication Number (TIN). The
TIN shows the manufacturer and plant code, tire size,
and date the tire was manufactured. The TIN is molded
onto both sides of the tire, although only one side
may have the date of manufacture.
(E) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.
(F) Uniform Tire Quality Grading (UTQG):Tire
manufacturers are required to grade tires based on
three performance factors: treadwear, traction,
and temperature resistance. For more information see
Uniform Tire Quality Grading on page 5-74.
(G) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. Passenger (P-Metric) Tire Example
5-62

(A) Temporary Use Only:The compact spare tire or
temporary use tire has a tread life of approximately
3,000 miles (5 000 km) and should not be driven
at speeds over 65 mph (105 km/h). The compact spare
tire is for emergency use when a regular road tire
has lost air and gone at. If your vehicle has a compact
spare tire, seeCompact Spare Tire on page 5-99
andIf a Tire Goes Flat on page 5-77.(B) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.
(C) Tire Identication Number (TIN):The letters
and numbers following the DOT (Department of
Transportation) code is the Tire Identication
Number (TIN). The TIN shows the manufacturer and
plant code, tire size, and date the tire was manufactured.
The TIN is molded onto both sides of the tire, although
only one side may have the date of manufacture.
(D) Maximum Cold Ination Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load.
(E) Tire Ination:The temporary use tire or compact
spare tire should be inated to 60 psi (420 kPa).
For more information on tire pressure and ination see
Ination - Tire Pressure on page 5-67.
(F) Tire Size:A combination of letters and numbers
dene a tire’s width, height, aspect ratio, construction
type and service description. The letter T as the
rst character in the tire size means the tire is for
temporary use only.
(G) 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. Compact Spare Tire Example
5-63

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

Occupant Distribution:Designated seating positions.
Outward Facing Sidewall:The side of an
asymmetrical tire that has a particular side that faces
outward when mounted on a vehicle. The side of the tire
that contains a whitewall, bears white lettering, or
bears manufacturer, brand, and/or model name molding
that is higher or deeper than the same moldings on
the other sidewall of the tire.
Passenger (P-Metric) Tire:A tire used on passenger
cars and some light duty trucks and multipurpose
vehicles.
Recommended Ination Pressure:Vehicle
manufacturer’s recommended tire ination pressure and
shown on the tire placard. SeeInation - Tire Pressure
on page 5-67andLoading Your Vehicle on page 4-33.
Radial Ply Tire:A pneumatic tire in which the ply cords
that extend to the beads are laid at 90 degrees to the
centerline of the tread.
Rim:A metal support for a tire and upon which the tire
beads are seated.
Sidewall:The portion of a tire between the tread and
the bead.
Speed Rating:An alphanumeric code assigned to a
tire indicating the maximum speed at which a tire
can operate.Traction:The friction between the tire and the road
surface. The amount of grip provided.
Tread:The portion of a tire that comes into contact
with the road.
Treadwear Indicators:Narrow bands, sometimes
called wear bars, that show across the tread of a tire
when only 1/16 inch (1.6 mm) of tread remains.
SeeWhen It Is Time for New Tires on page 5-71.
UTQGS (Uniform Tire Quality Grading Standards):A
tire information system that provides consumers with
ratings for a tire’s traction, temperature, and treadwear.
Ratings are determined by tire manufacturers using
government testing procedures. The ratings are molded
into the sidewall of the tire. SeeUniform Tire Quality
Grading on page 5-74.
Vehicle Capacity Weight:The number of designated
seating positions multiplied by 150 lbs (68 kg) plus
the rated cargo load. SeeLoading Your Vehicle
on page 4-33.
Vehicle Maximum Load on the Tire:Load on an
individual tire due to curb weight, accessory weight,
occupant weight, and cargo weight.
Vehicle Placard:A label permanently attached to a
vehicle showing the vehicle’s capacity weight and
the original equipment tire size and recommended
ination pressure. See “Tire and Loading Information
Label” underLoading Your Vehicle on page 4-33.
5-66

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