Page 234 of 320

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
first 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 certified
to carry. The load index can range from 1 to 279. The
speed rating is the maximum speed a tire is certified
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.
5-50
Page 243 of 320

{CAUTION:
Using the wrong replacement wheels, wheel
bolts or wheel nuts on your vehicle can be
dangerous. It could affect the braking and
handling of your vehicle, make your tires lose
air and make you lose control. You could have
a collision in which you or others could be
injured. Always use the correct wheel, wheel
bolts and wheel nuts for replacement.
Notice:The wrong wheel can also cause problems
with bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper height,
vehicle ground clearance and tire or tire chain
clearance to the body and chassis.
SeeChanging a Flat Tire on page 5-60for more
information.
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 “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.
5-59
Page 318 of 320

Safety Belts (cont.)
Rear Seat Passengers.................................1-19
Right Front Passenger Position......................1-19
Safety Belt Extender....................................1-25
Safety Belt Use During Pregnancy.................1-18
Safety Belts Are for Everyone......................... 1-6
Shoulder Belt Height Adjuster........................1-18
Safety Warnings and Symbols.............................. iii
Seats
Head Restraints............................................ 1-5
Manual........................................................ 1-2
Reclining Seatbacks...................................... 1-4
Six-Way Power Driver.................................... 1-3
Second-Gear Start..........................................2-22
Securing a Child Restraint
Center Rear Seat Position............................1-42
Designed for the LATCH System...................1-40
Rear Outside Seat Position...........................1-40
Right Front Seat Position..............................1-44
Selecting the Right Schedule, Maintenance.......... 6-5
Service........................................................... 5-3
Adding Equipment to the Outside of
Your Vehicle.............................................. 5-5
Doing Your Own Work................................... 5-4
Engine Soon Light.......................................3-30
Publications Ordering Information...................7-10
Vehicle Soon Light.......................................3-34
Servicing Your Airbag-Equipped Vehicle..............1-52Setting the Time
Radios with Radio Data Systems (RDS).........3-36
Radios without Radio Data Systems (RDS).....3-36
Sheet Metal Damage.......................................5-76
Shifting Into Park (P).......................................2-23
Shifting Out of Park (P)...................................2-24
Short Trip/City Scheduled Maintenance................ 6-6
Shoulder Belt Height Adjuster...........................1-18
Signals, Turn and Lane-Change.......................... 3-8
Spare Tire
Compact....................................................5-70
Installing....................................................5-63
Removing...................................................5-62
Storing.......................................................5-69
Specifications, Capacities.................................5-85
Speedometer..................................................3-24
Starting Your Engine.......................................2-17
Steering.......................................................... 4-8
Steering, Suspension and Front Drive Axle
Boot and Seal Inspection..............................6-20
Steering Wheel, Tilt Wheel................................. 3-6
Storage Areas
Center Console Storage Area........................2-28
Cupholder(s)...............................................2-28
Glove Box..................................................2-28
Stuck in Sand, Mud, Ice or Snow......................4-26
Sun Visors.....................................................2-14
10