Tire Terminology And Definitions - GMC 2014 Sierra Owner's Manual

a light truck tire engineered to
standards set by the U.S. Tire
and Rim Association.
The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
A two-digit
number that indicates the tire
height-to-width measurements.
For example, if the tire size
aspect ratio is 75, as shown in
item 3 of the light truck
(LT-Metric) tire illustration, it
would mean that the tire's
sidewall is 75 percent as high as
it is wide.
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; and the letter B
means belted-bias ply
construction.
the wheel in inches.
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.
A letter
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).
Diameter of
combined weight of optional
accessories. Some examples of
Load Range.
optional accessories are
The
automatic transmission, power
windows, power seats, and air
conditioning.
of a tire's height to its width.
cords between the plies and the
tread. Cords may be made from
steel or other reinforcing
materials.
steel wires wrapped by steel
cords that hold the tire onto
The amount of
the rim.
The
The relationship
A rubber coated layer of
The tire bead contains