Tire Terminology And Definitions - GMC Sierra 2023 Manual

120 Vehicle Care
(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).
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 kPa
(kilopascal) or psi (pounds per square
inch) before a tire has built up heat
from driving. See Tire Pressure 0 121.
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 75.
GAWR FRT Gross Axle Weight Rating
:
for the front axle. See Vehicle Load
Limits 0 75.
GAWR RR Gross Axle Weight Rating
:
for the rear axle. See Vehicle Load
Limits 0 75.
Intended Outboard Sidewall
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-Metric) Tire
on light duty trucks and some
multipurpose passenger vehicles.
Load Index An assigned number
:
ranging from 1 to 279 that corresponds
to the load carrying capacity of a tire.
Maximum Inflation Pressure
maximum air pressure to which a cold
tire can 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.
Occupant Distribution Designated
:
seating positions.
The side
:
A tire used
:
The
: