Tire Terminology And Definitions - GMC 2009 Savana Van Owner's Manual

(D) Construction Code
to 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) Load Range Load Range.
:
(G) Service Description
indicates the load index and speed rating of a tire.
If two numbers are given as in the example,
120/116, then this represents the load index for
single versus dual wheel usage (single/dual).
The speed rating is the maximum speed a tire is
certified to carry a load. This does not apply to
Goodyear LT225/75R16 G949 RSA and Goodyear
LT225/75R16 G933 RSD commercial truck tires;
see the dual tire and single tire maximum load and
load range letter designations on the tire sidewall.
5-60
A letter code is used
:
The service description
:
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.
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 5-63.
The amount of air pressure