Tire Designations - GMC Terrain 2010 Owner's Manual

9-48 Vehicle Care

Tire Designations

Tire Size
The following illustration shows
an example of a typical
passenger vehicle tire size.
(A) Passenger (P Metric) Tire
The United States version of a
metric tire sizing system. The
letter P as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire
and Rim Association.
(B) Tire Width
:
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(C) Aspect Ratio
number that indicates the tire
height to width measurements.
For example, if the tire size
aspect ratio is 60, as shown in
item C of the illustration, it would
mean that the tire's sidewall is
60 percent as high as it is wide.
:
(D) Construction Code
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; and the
letter B means belted bias ply
construction.
The three digit (E) Rim Diameter
the wheel in inches.
(F) Service Description
characters represent the load
A two digit index and speed rating of the
:
tire. The load index represents
the load carry capacity a tire is
certified to carry. The speed
rating is the maximum speed a
tire is certified to carry a load.
A
:
Diameter of
:
These
: