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Maintenance
Tire Terminology and Definitions
Air Pressure
The amount of air inside the tire
pressing outward on the tire. Air
pressure is expressed in kilopascal
(kPa) or pounds per square inch(psi).
Accessory Weight
This means the combined weight of
optional accessories. Some exam-
ples of optional accessories are
automatic transmission, power
seats, and air conditioning.
Aspect Ratio
The relationship of a tire's height toits 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 thetread.
Cold Tire Pressure
The amount of air pressure in a tire,
measured in kilopascals (kPa) or
pounds per square inch (psi) before
a tire has built up heat from driving.
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
The DOT code includes the TireIdentification Number (TIN), an
alphanumeric designator which can
also identify the tire manufacturer,
production plant, brand and date ofproduction.
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.
