9-60 Vehicle Care
Summer Performance Tires
Many General Motors high
performance models come
factory-equipped with tires that
are optimized for maximum dry
and wet road performance while
still retaining satisfactory tread
life, excellent durability, and low
noise levels. In severe winter
climates where snowfall may be
significant, these tires may be
found to provide less traction.
Tire Sidewall Labeling
Useful information about a tire is
molded into its sidewall. The
examples below show a typical
passenger vehicle tire and a
compact spare tire sidewall.
Passenger (P-Metric) Tire Example
(A) Tire Size: The tire size is a
combination of letters and
numbers used to define a
particular tire's width, height,
aspect ratio, construction type,
and service description. See the
“Tire Size” illustratio n later in this
section for more detail.
(B) 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.
(C) DOT (Department of
Transportation)
: The
Department of Transportation
(DOT) code indicates that the
tire is in compliance with
the U.S. Department of
Transportation Motor Vehicle
Safety Standards.
(D) Tire Identification Number
(TIN)
: The letters and numbers
following the DOT (Department
of Transportation) code is the
Tire Identification Number (TIN).