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Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service,
see your GM Warranty booklet for details. For additional
information refer to the tire manufacturer's booklet
included with your vehicle's Owner Manual.
{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. See
Loading Your
Vehicle on page 4-29.
·Underin¯ated 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.
CAUTION: (Continued)
CAUTION: (Continued)
·
Overin¯ated tires are more likely to be cut,
punctured, or broken by a sudden
impact Ð 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.
See
In¯ation - Tire Pressure on page 5-58for
in¯ation pressure adjustment for high speed
driving.
Notice:If your vehicle has low-pro®le tires, they
are more susceptible to damage from road hazards
or curb impact than standard pro®le 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
in¯ation pressure and, when possible avoid contact
with curbs, potholes, and other road hazards.
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Winter Tires
If you expect to drive on snow or ice covered roads often,
you may want to get winter tires for your vehicle. High
performance tires, like the original equipment tires
installed on your vehicle, are designed for very
responsive driving on wet or dry pavement and may not
offer the traction you would like or the same level of
performance as winter tires on snow or ice covered
roads.
Winter tires, in general, are designed for increased
traction on snow and ice covered roads. With winter
tires, there may be decreased dry road traction,
increased road noise, and shorter tire tread life. After
switching to winter tires, be alert for changes in vehicle
handling and braking.
See your dealer for details regarding winter tire
availability and proper tire selection. Also, see
Buying
New Tires on page 5-63
If you choose to use winter tires:
·Use tires of the same brand and tread type on all
four wheel positions.
·Use only radial ply tires of the same size as your
original equipment tires.
Winter tires with the same speed rating as your original
equipment tires may not be available for H, V, W, Y,
and ZR speed rated tires. If you choose winter tires with
a lower speed rating, never exceed the tire's speed
capability.
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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 de®ne a particular tire's width,
height, aspect ratio, construction type, and service
description. See the ªTire Sizeº illustration later in this
section for more detail.(B) TPC Spec (Tire Performance Criteria
Speci®cation):Original equipment tires designed to
GM's speci®c tire performance criteria have a TPC
speci®cation code molded onto the sidewall. GM's TPC
speci®cations 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 Identi®cation Number (TIN):The letters and
numbers following DOT (Department of Transportation)
code is the Tire Identi®cation 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 5-64.
(G) Maximum Cold In¯ation Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load. Passenger (P-Metric) Tire Example
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(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, see
Compact Spare Tire on page 5-76andIf a Tire Goes Flat on page 5-68.
(B) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.(C) Tire Identi®cation Number (TIN):The letters and
numbers following the DOT (Department of
Transportation) code is the Tire Identi®cation 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 In¯ation Load Limit:Maximum
load that can be carried and the maximum pressure
needed to support that load.
(E) Tire In¯ation:The temporary use tire or compact
spare tire should be in¯ated to 60 psi (420 kPa).
For more information on tire pressure and in¯ation see
In¯ation - Tire Pressure on page 5-58.
(F) Tire Size:A combination of letters and numbers
de®ne 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
Speci®cation):Original equipment tires designed to
GM's speci®c tire performance criteria have a TPC
speci®cation code molded onto the sidewall. GM's TPC
speci®cations meet or exceed all federal safety
guidelines. Compact Spare Tire Example
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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 certi®ed
to carry. The load index can range from 1 to 279. The
speed rating is the maximum speed a tire is certi®ed
to carry a load. Speed ratings range from A to Z.
Tire Terminology and De®nitions
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.
Belt:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be made
from steel or other reinforcing materials.
Bead:The tire bead contains steel wires wrapped by
steel cords that hold the tire onto the rim.
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Bias Ply Tire:A pneumatic tire in which the plies are
laid at alternate angles less than 90 degrees to the
centerline of the tread.
Cold In¯ation Pressure:The amount of air pressure in
a tire, measured in pounds per square inch (psi) or
kilopascals (kPa) before a tire has built up heat
from driving. See
In¯ation - Tire Pressure on page 5-58.
Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment including
the maximum capacity of fuel, oil and coolant, but
without passengers and cargo.
DOT Markings:A code molded into the sidewall of a
tire signifying that the tire is in compliance with the U.S.
Department of Transportation (DOT) motor vehicle
safety standards. The DOT code includes the Tire
Identi®cation Number (TIN), an alphanumeric designator
which can also identify the tire manufacturer, production
plant, brand and date of production.
GVWR:Gross Vehicle Weight Rating, see
Loading
Your Vehicle on page 4-29.
GAWR FRT:Gross Axle Weight Rating for the front
axle, see
Loading Your Vehicle on page 4-29.
GAWR RR:Gross Axle Weight Rating for the rear axle,
see
Loading Your Vehicle on page 4-29.Intended Outboard Sidewall:The side of an
asymmetrical tire, that must always face outward when
mounted on a vehicle.
Kilopascal (kPa):The metric unit for air pressure.
Light Truck (LT-Metric) Tire:A tire used on light duty
trucks and some multipurpose passenger vehicles.
Load Index:An assigned number ranging from
1 to 279 that corresponds to the load carrying capacity
of a tire.
Maximum In¯ation Pressure:The maximum air
pressure to which a cold tire may be in¯ated. The
maximum air pressure is molded onto the sidewall.
Maximum Load Rating:The load rating for a tire at the
maximum permissible in¯ation pressure for that tire.
Maximum Loaded Vehicle Weight:The sum of curb
weight; accessory weight; vehicle capacity weight;
and production options weight.
Normal Occupant Weight:The number of occupants a
vehicle is designed to seat multiplied by 150 lbs (68 kg).
See
Loading Your Vehicle on page 4-29.
Occupant Distribution:Designated seating positions.
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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 In¯ation Pressure:Vehicle
manufacturer's recommended tire in¯ation pressure and
shown on the tire placard. See
In¯ation - Tire Pressure
on page 5-58andLoading Your Vehicle on page 4-29.
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.
See
When It Is Time for New Tires on page 5-62.
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. See
Uniform Tire Quality
Grading on page 5-64.
Vehicle Capacity Weight:The number of designated
seating positions multiplied by 150 lbs (68 kg) plus
the rated cargo load. See
Loading Your Vehicle
on page 4-29.
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
in¯ation pressure. See ªTire and Loading Information
Labelº under
Loading Your Vehicle on page 4-29.
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In¯ation - Tire Pressure
Tires need the correct amount of air pressure to operate
effectively.
Notice:Do not let anyone tell you that
under-in¯ation or over-in¯ation is all right. It is not.
If your tires do not have enough air (under-in¯ation),
you can get the following:
·Too much ¯exing
·Too much heat
·Tire overloading
·Premature or irregular wear
·Poor handling
·Reduced fuel economyIf your tires have too much air (over-in¯ation), you
can get the following:
·Unusual wear
·Poor handling
·Rough ride
·Needless damage from road hazards
A Tire and Loading Information label is attached to your
vehicle's center pillar, below the driver's door latch.
This label lists your vehicle's original equipment
tires and their recommended cold tire in¯ation pressures.
The recommended cold tire in¯ation pressure, shown
on the label, is the minimum amount of air pressure
needed to support your vehicle's maximum load carrying
capacity. For more information regarding how much
weight your vehicle can carry, see
Loading Your Vehicle
on page 4-29.
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