(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.
Vehicle Care
(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.
(E) Rim Diameter
the wheel in inches.
(F) Service Description
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.
9-51
A two-digit
:
A
:
Diameter of
:
These
: