TIRES
DESCRIPTION
TIRES
Tires are designed and engineered for each specific vehicle. They providethe best overall performance for normal
operation. The ride and handling characteristics match the vehicle’s requirements. With proper care they will give
excellent reliability, traction,skid resistance, and tread life.
Driving habits have more effect on tire life than any other factor. Carefuldrivers will obtain in most cases, much
greater mileage than severe use or careless drivers. A few of the driving habits which will shorten the life of any tire
are:
Rapid acceleration
Severe brake applications
High speed driving
Excessive speeds on turns
Striking curbs and other obstacles
Radial-ply tires are more prone to irregular tread wear. It is important tofollow the tire rotation interval (Refer to 22
- TIRES/WHEELS - STANDARD PROCEDURE). This will help to achieve a greater tread life.
TIRE IDENTIFICATION
Tire type, size, aspect ratio and speed rating are
encoded in the letters and numbers imprinted on the
side wall of the tire. Refer to the chart to decipher the
tire identification code.
Performance tires have a speed rating letter after the
aspect ratio number. The speed rating is not always
printed on the tire sidewall. These ratings are:
Qup to 100 mph
Sup to 112 mph
Tup to 118 mph
Uup to 124 mph
Hup to 130 mph
Vup to 149 mph
Zmore than 149 mph (consult the tire manufac-
turer for the specific speed rating)
An All Season type tire will have eitherM+S,M&SorM–S(indicating mud and snow traction) imprinted on the
side wall.
TIRE CHAINS
Tire snow chains may be used oncertainmodels. Refer to the Owner’s Manual for more information.
SPARE / TEMPORARY TIRE
The temporary spare tire is designed for emergency use only. The original tire should be repaired or replaced at the
first opportunity, then reinstalled. Do not exceed speeds of 80 KMH (50 MPH). when using the temporary spare tire.
Refer to Owner’s Manual for complete details.
RADIAL – PLY TIRES
Radial-ply tires improve handling, tread life and ride quality, and decrease rolling resistance.
Radial-ply tires must always be used in sets of four. Under no circumstances should they be used on the front only.
They may be mixed with temporary spare tires when necessary. A maximum speedof80KMH(50MPH)isrec-
ommended while a temporary spare is in use.
WHEEL DESIGN
The rim size is on the vehicle safety certification label
located on the drivers door shut face. The size of the
rim is determined by the drivetrain package. Original
equipment wheels/rims are designed for operation up
to the specified maximum vehicle capacity.
All models use stamped steel, cast aluminum or
forged aluminum wheels. Every wheel has raised sec-
tions between the rim flanges (1) and rim drop well (3)
called safety humps.
Initial inflation of the tire forces the bead over these
raised sections. In case of rapid loss of air pressure,
the raised sections help hold the tire on the wheel.
The wheel studs and nuts are designed for specific
applications. All aluminum and some steel wheels
have wheel stud nuts with an enlarged nose. This
enlarged nose is necessary to ensure proper retention
of the wheels. Do not use replacement studs or nuts with a different design orlesserquality.
DIAGNOSIS AND TESTING
WHEEL INSPECTION
Inspect wheels for:
Excessive run out
Dents or cracks
Damaged wheel lug nut holes
Air Leaks from any area or surface of the rim
NOTE: Do not attempt to repair a wheel by hammering, heating or welding.
If a wheel is damaged an original equipment replacement wheel should be used. When obtaining replacement
wheels, they should be equivalent in load carrying capacity. The diameter, width, offset, pilot hole and bolt circle of
the wheel should be the same as the original wheel.
WARNING: Failure to use equivalent replacement wheels may adversely affect the safety and handling of
the vehicle. Used wheels are not recommended. The service history of the wheel may have included severe
treatment or very high mileage. The rim could fail without warning.
STANDARD PROCEDURE
WHEEL REPLACEMENT
The wheel studs and nuts are designed for specific applications. They mustbe replaced with equivalent parts. Do
not use replacement parts of lesser quality or a substitute design. All aluminum and some steel wheels have wheel
stud nuts which feature an enlarged nose. This enlarged nose is necessary to ensure proper retention of the alu-
minum wheels.
