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.
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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.
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 Tire 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. SeeIn ation - Tire Pressure on page 5-63.
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. SeeLoading
Your Vehicle on page 4-31.GAWR FRT:Gross Axle Weight Rating for the front
axle. SeeLoading Your Vehicle on page 4-31.
GAWR RR:Gross Axle Weight Rating for the rear axle.
SeeLoading Your Vehicle on page 4-31.
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).
SeeLoading Your Vehicle on page 4-31.
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{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different
sizes, 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, brands, or types may also
cause damage to your vehicle. Be sure to
use the correct size, brand, and type of tires
on all wheels. It is all right to drive with
your compact spare temporarily, as it was
developed for use on your vehicle. See
Compact Spare Tire on page 5-83.
{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).
SeeLoading Your Vehicle on page 4-31, for more
information about the Tire and Loading Information
Label and its location on your vehicle.
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Care of Safety Belts
Keep belts clean and dry.
{CAUTION:
Do not bleach or dye safety belts. If you do,
it may severely weaken them. In a crash,
they might not be able to provide adequate
protection. Clean safety belts only with mild
soap and lukewarm water.
Weatherstrips
Silicone grease on weatherstrips will make them last
longer, seal better, and not stick or squeak. Apply
silicone grease with a clean cloth. During very cold,
damp weather frequent application may be required.
SeeRecommended Fluids and Lubricants on page 6-12.
Washing Your Vehicle
The paint nish on the vehicle provides beauty, depth
of color, gloss retention, and durability.
The best way to preserve the vehicle’s nish is to keep it
clean by washing it often with lukewarm or cold water.
Do not wash the vehicle in the direct rays of the sun.
Use a car washing soap. Do not use strong soaps
or chemical detergents. Be sure to rinse the vehicle well,
removing all soap residue completely. GM-approved
cleaning products can be obtained from your dealer.
SeeVehicle Care/Appearance Materials on page 5-91.
Do not use cleaning agents that are petroleum
based, or that contain acid or abrasives. All cleaning
agents should be ushed promptly and not allowed
to dry on the surface, or they could stain. Dry the
nish with a soft, clean chamois or an all-cotton towel
to avoid surface scratches and water spotting.
High pressure car washes may cause water to enter
the vehicle.
Cleaning Exterior Lamps/Lenses
Use only lukewarm or cold water, a soft cloth and a
car washing soap to clean exterior lamps and lenses.
Follow instructions underWashing Your Vehicle on
page 5-87.
5-87