Maintenance
9-30
Wheel Alignment and Tire
Balance
The wheels on your vehicle were aligned
and balanced carefully at the factory to
give you the longest tire life and best
overall performance.
In most cases, you will not need to have
your wheels aligned again. However,
if you notice unusual tire wear or your
vehicle pulling one way or the other, the
alignment may need to be reset.
If you notice your vehicle vibrating when
driving on a smooth road, your wheels
may need to be rebalanced.
NOTICE
Improper wheel weights can damage
your vehicle’s aluminum wheels. Use
only approved wheel weights.
Tire Replacement
Tread wear indicatorTread wear indicator
OLMB073027
If the tire is worn evenly, a tread wear
indicator will appear as a solid band
across the tread. This shows there is
less than 1/16 inch (1.6 mm) of tread left
on the tire. Replace the tire when this
happens.
Do not wait for the tread surface to
become level with the tread wear
indicators before replacing the tire.
09
9-35
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.
Maintenance
9-36
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 motor vehicle safety
standards. The DOT code includes the
Tire Identification Number (TIN), an
alphanumeric designator which can
also identify the tire manufacturer,
production plant, brand and date of
production.
GVWR
Gross Vehicle Weight Rating
GAWR FRT
Gross Axle Weight Rating for the Front
Axle.
GAWR RR
Gross Axle Weight Rating for the Rear
axle.
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) tire
A tire designated by its manufacturer as
primarily intended for use on lightweight
trucks or multipurpose passenger
vehicles.
Load ratings
The maximum load that a tire is rated to
carry for a given inflation pressure.
Load Index
An assigned number ranging from 1 to
279 that corresponds to the load carrying
capacity of a tire.
Maximum Inflation Pressure
The maximum air pressure to which a
cold tire may be inflated. The maximum
air pressure is molded onto the sidewall.
Maximum Load Rating
The load rating for a tire at the maximum
permissible inflation 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
pounds (68 kg).
Occupant Distribution
Designated seating positions.
Outward Facing Sidewall
An asymmetrical tire has a particular
side that faces outward when mounted
on a vehicle. The outward facing
sidewall bears white lettering or bears
manufacturer, brand, and/or model
name molding that is higher or deeper
than the same moldings on the inner
facing sidewall.
Passenger (P-Metric) tire
A tire used on passenger cars and some
light duty trucks and multipurpose
vehicles.
09
9-37
Ply
A layer of rubber-coated parallel cords.
Pneumatic tire
A mechanical device made of rubber,
chemicals, fabric and steel or other
materials, that, when mounted on an
automotive wheel provides the traction
and contains the gas or fluid that
sustains the load.
Pneumatic options weight
The combined weight of installed regular
production options weighing over 5 lb.
(2.3 kg) in excess of the standard items
which they replace, not previously
considered in curb weight or accessory
weight, including heavy duty breaks, ride
levelers, roof rack, heavy duty battery,
and special trim.
Recommended Inflation Pressure
Vehicle manufacturer’s recommended
tire inflation pressure as shown on the
tire placard.
Radial Ply Tire
A pneumatic tire in which the ply cords
that extend to the beads are laid at 90
degrees to the centerline of the tread.
Rim
A metal support for a tire and upon
which the tire beads are seated.
Sidewall
The portion of a tire between the tread
and the bead.
Speed Rating
An alphanumeric code assigned to a tire
indicating the maximum speed at which
a tire can operate.
Traction
The friction between the tire and
the road surface. The amount of grip
provided.
Tread
The portion of a tire that comes into
contact with the road.
Treadwear Indicators
Narrow bands, sometimes called “wear
bars”, that show across the tread of a tire
when only 1/16 inch of tread remains.
UTQGS
Uniform Tire Quality Grading Standards
is a tire information system that provides
consumers with ratings for a tire’s
traction, temperature and treadwear.
Ratings are determined by tire
manufacturers using government testing
procedures. The ratings are molded into
the sidewall of the tire.
Vehicle Capacity Weight
The number of designated seating
positions multiplied by 150 lbs. (68 kg)
plus the rated cargo and luggage load.
Vehicle Maximum Load on the Tire
Load on an individual tire due to curb
and accessory weight plus maximum
occupant and cargo weight.
Vehicle Normal Load on the Tire
Load on an individual tire that is
determined by distributing to each axle
its share of the curb weight, accessory
weight, and normal occupant weight and
dividing by 2.
Vehicle Placard
A label permanently attached to a vehicle
showing the original equipment tire size
and recommended inflation pressure.
Index
I-12
Tire Care ........................................................................\
...................................9-27
Tire Maintenance ........................................................................\
......................9-32
Tire Replacement ........................................................................\
.....................9-30
Tire Rotation ........................................................................\
............................. 9-29
Tire Sidewall Labeling ........................................................................\
.............9-32
Tire
Terminology and Definitions
.................................................................... 9-35
Tire T
raction
........................................................................\
............................. 9-32
Wheel Alignment and
Tire Balance
................................................................. 9-30
Wheel Replacement ........................................................................\
.................. 9-32
T
owing
........................................................................\
......................................... 8-20
Emergency towing ........................................................................\
....................8-22
Emergency T
owing
........................................................................\
.................. 8-21
Removable towing hook ........................................................................\
...........8-21
Towing Service ........................................................................\
......................... 8-20
T
railer Towing
........................................................................\
............................. 6-54
T
runk
........................................................................\
............................................ 5-61
Emergency trunk safety release ........................................................................\
5-62
Smart Trunk
release
........................................................................\
.................. 5-63
V
V
ehicle Break-In Process
........................................................................\
............... 1-7
V
ehicle Certification Label
........................................................................\
.......... 2-13
Vehicle Data Collection and Event Data Recorders
.............................................. 1-8
V
ehicle Identification Number (
VIN) .................................................................. 2-13
V
ehicle load limit
........................................................................\
......................... 6-49
Tire Loading Information Label .......................................................................6-50
V
ehicle Modifications
........................................................................\
.................... 1-7
V
olume and Weight
........................................................................\
...................... 2-10