Tire Size - Chevrolet 2010 Corvette Convertible Owner's Manual

(F) Uniform Tire Quality Grading (UTQG)
manufacturers are required to grade tires based
on three performance factors: treadwear, traction
and temperature resistance. For more information
see
(G) Maximum Cold Inflation Load Limit
Maximum load that can be carried and the
maximum pressure needed to support that load.

Tire Size

The following illustration shows an example of a
typical passenger (p metric) vehicle tire size.
(A) Passenger (P Metric) Tire
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.
Tire
:
.
:
The United
:
(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 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
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
represent the load 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 letter code is used
:
These characters
:
6-65