Tire Terminology And Definitions - Chevrolet 2008 Express Owner's Manual

(D) Construction Code
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
indicates the load range and speed rating of a
tire. The load index can range from 1 to 279.
Speed ratings range from A to Z.
Tire Terminology and Definitions
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.
A letter code is used to
:
The service description
:
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
:
in a tire, measured in pounds per square inch
(psi) or kilopascals (kPa) before a tire has built up
heat from driving. See Inflation - Tire Pressure
on page 5-64.
Curb Weight 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.
The amount of air pressure
5-61