Tire Terminology And Definitions - GMC Sierra 2500 HD2022 Owner's Manual

346 Vehicle Care
(4) Construction Code A letter code is
:
used 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.
(5) Rim Diameter Diameter of the
:
wheel in inches.
(6) Load Range Load Range.
:
(7) Service Description The 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.

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 kPa (kilopascal) or psi
(pounds per square inch).
Accessory Weight The combined
:
weight of optional accessories. Some
examples of optional accessories are
automatic transmission, 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
:
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 kPa
(kilopascal) or psi (pounds per square
inch) before a tire has built up heat
from driving. See Tire Pressure 0 348.
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.
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 (DOT)
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.
:
See Vehicle Load Limits 0 220.
GAWR FRT Gross Axle Weight Rating
:
for the front axle. See Vehicle Load
Limits 0 220.
GAWR RR Gross Axle Weight Rating
:
for the rear axle. See Vehicle Load
Limits 0 220.