Tire Size - GMC 2005 Canyon Owner's Manual

Tire Size

The following illustration shows an example of a typical
passenger vehicle tire size.
(A) 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: The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.
(C) Aspect Ratio: A two-digit number that indicates the
tire height-to-width measurements. For example,
if the tire size aspect ratio is 70, as shown in item C of
the illustration, it would mean that the tire's sidewall
is 70 percent as high as it is wide.
(D) 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; and the
letter B means belted-bias ply construction.
(E) Rim Diameter: Diameter of the wheel in inches.
(F) Service Description: These characters represent
the load range and speed rating of the tire. The load
index represents the load carry capacity a tire is certified
to carry. The load index can range from 1 to 279.
The speed rating is the maximum speed a tire is certified
to carry a load. Speed ratings range from A to Z.
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