Maintenance9-36
Wheel Replacement
When replacing the metal wheels
for any reason, make sure the new
wheels are equivalent to the original
factory units in diameter, rim width
and offset.
Tire Traction
Tire traction can be reduced if you
drive on worn tires, tires that are
improperly inflated or on slippery
road surfaces. Tires should be
replaced when the tread depth is at
least 2/32 inch (1.6 mm). To reduce
the possibility of losing control, slow
down whenever there is rain, snow
or ice on the road.
Tire Maintenance
In addition to proper inflation,
correct wheel alignment helps to
decrease tire wear. If you find a tire
is worn unevenly, have your dealer
check the wheel alignment.
When you have new tires installed,
make sure they are balanced. This
will increase vehicle ride comfort
and tire life. Additionally, a tire
should always be rebalanced if it is
removed from the wheel.
Tire Sidewall Labeling
This information identifies and
describes the fundamental
characteristics of the tire and also
provides the tire identification
number (TIN) for safety standard
certification. The TIN can be used to
identify the tire in case of a recall.
OLMB073028
1. Manufacturer or brand name
Manufacturer or brand name is
shown.
2. Tire size designation
A tire’s sidewall is marked with a
tire size designation. You will need
this information when selecting
replacement tires for your car.
The following explains what the
letters and numbers in the tire size
designation mean.
Example tire size designation:
(These numbers are provided as
an example only; your tire size
designator could vary depending on
your vehicle.)
205/55R16 91H
205 - Tire width in millimeters.
55 - Aspect ratio. The tire’s section height as a percentage of its width.
R - Tire construction code (Radial).
16 - Rim diameter in inches.
91 - Load Index, a numerical code associated with the maximum load
the tire can carry.
H - Speed Rating Symbol. See the speed rating chart in this section for
additional information.
09
9-39
Temperature A, B & C
The temperature grades are A (the
highest), B and C representing the
tire’s resistance to the generation
of heat and its ability to dissipate
heat when tested under controlled
conditions on a specified indoor
laboratory test wheel.
Sustained high temperature can
cause the material of the tire to
degenerate and reduce tire life, and
excessive temperature can lead to
sudden tire failure. Grade C responds
to a level of performance which
all passenger car tires must meet
under the Federal Motor Vehicle
Safety Standard No. 109. Grades
B and A represent higher levels of
performance on the laboratory test
wheel than the minimum required
by law.
WARNING
The temperature grade for this
tire is established for a tire that
is properly inflated and not
overloaded. Excessive speed,
under-inflation, over-inflation, or
excessive loading, either separately
or in combination, can cause heat
build-up and possible sudden
tire failure. This may cause loss
of vehicle control resulting in an
accident.
Tire Terminology and Definitions
Air Pressure
The amount of air inside the tire
pressing outward on 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
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.
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.
