Tire designations – CHEVROLET 2010 Camaro User Manual
Page 283

(E) Tire Inflation
:
The
temporary use tire or compact
spare tire should be inflated
to 60 psi (420 kPa). For more
information on tire pressure
and inflation see Tire Pressure
on page 9-54.
(F) Tire Size
:
A combination
of letters and numbers define a
tire’s width, height, aspect ratio,
construction type, and service
description. The letter T as the
first character in the tire size
means the tire is for temporary
use only.
(G) TPC Spec (Tire
Performance Criteria
Specification)
:
Original
equipment tires designed to
GM’s specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM’s TPC specifications meet
or exceed all federal safety
guidelines.
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
:
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
:
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
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.
Vehicle Care
9-51