(F) Tire Ply Material:The type of cord and number of
plies in the sidewall and under the tread.
(G) Single Tire Maximum Load:Maximum load that
can be carried and the maximum pressure needed
to support that load when used as a single. For
information on recommended tire pressure see
In¯ation - Tire Pressure on page 5-63andLoading Your
Vehicle on page 4-51.
Tire Size
The following examples show the different parts of a
tire size.(A) Passenger (P-Metric) Tire:The United States
version of a metric tire sizing system. The letter ªPº 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 ª75,º as shown in item ªCº of
the illustration, it would mean that the tire's sidewall is
75% 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 ªRº means radial ply construction; the letter ªDº
means diagonal or bias ply construction; and the
letter ªBº means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:The service description
indicates the load range and speed rating of a tire. The
load index can range from 1 to 279. Speed ratings
range from ªAº to ªZº. The light truck tire size example
above shows dual or single tire con®gurations. Passenger (P-Metric) Tire
5-59
(A) Light Truck (LT-Metric) Tire:The United States
version of a metric tire sizing system. The letter ªLTº as
the ®rst two characters in the tire size means a light
truck 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 ª75,º as shown in item ªCº of
the illustration, it would mean that the tire's sidewall is
75% 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 ªRº means radial ply construction; the letter ªDº
means diagonal or bias ply construction; and the
letter ªBº means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:The service description
indicates the load range and speed rating of a tire. The
load index can range from 1 to 279. Speed ratings
range from ªAº to ªZº. The light truck tire size example
above shows dual or single tire con®gurations.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. Light Truck (LT-Metric) Tire
5-60
Buying New Tires
To ®nd out what kind and size of tires you need, look at
the Tire and Loading Information label. For information
about this label and where to ®nd it, see
Loading
Your Vehicle on page 4-51.
The tires installed on your vehicle when it was new had
a Tire Performance Criteria Speci®cation (TPC Spec)
number on each tire's sidewall. When you get new tires,
GM recommends that you get tires with that same
TPC Spec number. That way your vehicle will continue
to have tires that are designed to give proper
endurance, handling, speed rating, load range, traction,
ride, tire pressure monitoring system performance
and other things during normal service on your vehicle.
If your tires have an all-season tread design, the
TPC number will be followed by an ªMSº (for mud
and snow).
If you ever replace your tires with those not having a
TPC Spec number, make sure they are the same
size, load range, speed rating and construction type
(bias, bias-belted or radial) as your original tires.
{CAUTION:
Mixing tires could cause you to lose control
while driving. If you mix tires of different sizes
or types (radial and bias-belted tires), the
vehicle may not handle properly, and you
could have a crash. Using tires of different
sizes may also cause damage to your vehicle.
Be sure to use the same size and type tires on
all wheels.
{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.
5-67
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You can't know how it's been used
or how far it's been driven. It could fail
suddenly and cause a crash. If you have to
replace a wheel, use a new GM original
equipment wheel.
Tire Chains
Notice:Use tire chains only where legal and only
when you must. Use only SAE Class ªSº type chains
that are the proper size for your tires. Install them
on the tires of the drive axle (four-wheel-drive
vehicles can use chains on both axles). 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.
5-71
10. Tighten the wheel nuts
®rmly in a crisscross
sequence as shown.
{CAUTION:
Incorrect wheel nuts or improperly tightened
wheel nuts can cause the wheel to come loose
and even come off. This could lead to an
accident. Be sure to use the correct wheel
nuts. If you have to replace them, be sure to
get new GM original equipment wheel nuts.
Stop somewhere as soon as you can and have
the nuts tightened with a torque wrench to the
proper torque speci®cation. See ªCapacities
and Speci®cationsº in the Index for wheel nut
torque speci®cation.
Notice:Improperly tightened wheel nuts can lead
to brake pulsation and rotor damage. To avoid
expensive brake repairs, evenly tighten the wheel
nuts in the proper sequence and to the proper
torque speci®cation. See ªCapacities and
Speci®cationsº in the index for the wheel nut torque
speci®cation.
When you reinstall the full-size wheel and tire, you
must also reinstall the plastic nut caps.
11. Tighten the plastic nut caps by hand. Then tighten
them one half turn with the wheel wrench. Do not
overtighten the nut caps or they may break.
5-83
Shifting Out of Park (P)...................................2-27
Short Trip/City De®nition.................................... 6-5
Short Trip/City Intervals..................................... 6-5
Short Trip/City Scheduled Maintenance................ 6-7
Shoulder Belt Height Adjuster...........................1-17
Skidding........................................................4-15
Some Other Rainy Weather Tips.......................4-34
Special Fabric Cleaning Problems.....................5-87
Speci®cations, Capacities.................................5-98
Speedometer..................................................3-28
Stalling on an Incline.......................................4-27
Starter Switch Check.......................................6-26
Starting Your Engine.......................................2-14
Steering........................................................4-10
Steering in Emergencies..................................4-12
Steering, Suspension and Front Drive Axle Boot
and Seal Inspection.....................................6-28
Steering Tips..................................................4-10
Storage Areas
Coinholder(s)..............................................2-33
Convenience Net.........................................2-36
Cupholder(s)...............................................2-33
Glove Box..................................................2-33
Luggage Carrier..........................................2-34
Storing a Flat or Spare Tire and Tools...............5-84
Stuck in Sand, Mud, Ice or Snow......................4-44
Sun Visors.....................................................2-11
Supplemental Restraint System (SRS)...............1-52
Adding Equipment to Your Air Bag-Equipped
Vehicle...................................................1-59Supplemental Restraint System (SRS) (cont.)
How Does an Air Bag Restrain?....................1-56
Servicing Your Air Bag-Equipped Vehicle.........1-58
What Makes an Air Bag In¯ate?....................1-55
What Will You See After an Air Bag
In¯ates?..................................................1-56
When Should an Air Bag In¯ate?...................1-55
Where Are the Air Bags?..............................1-54
T
Tachometer....................................................3-28
Tailgate........................................................... 2-9
Tailgate Lock Release....................................... 2-9
Throttle System Inspection...............................6-29
Tilt Wheel........................................................ 3-5
Tire In¯ation Check.........................................6-24
Tire Sidewall Labeling......................................5-56
Tire Size.......................................................5-59
Tire Terminology and De®nitions........................5-60
Tires.............................................................5-55
Buying New Tires........................................5-67
Chains.......................................................5-71
Changing a Flat Tire....................................5-72
If a Tire Goes Flat.......................................5-72
In¯ation - Tire Pressure................................5-63
Inspection and Rotation................................5-64
Uniform Tire Quality Grading.........................5-68
Wheel Alignment and Tire Balance.................5-69
12