Owner's Manual

10-44 Vehicle Care
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 descripti on. See the
“Tire Size” illustration later in
this section for more detail.
(B) TPC Spec (Tire
Performance Criteria
Specification)
: Original
equipment tires designed to
GM's specific tire performa nce
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 Identificati on
Number (TIN). The TIN shows
the manufacturer and plant
code, tire size, and date the tire
was manufactured. The TIN is
molded onto both sides of the
tire, although only one side may
have the date of manufacture.
(E) Tire Ply Material
: The type
of cord and number of plies in
the sidewall and under the tread.
(F) Uniform Tire Quality
Grading (UTQG)
: Tire
manufacturers are required to
grade tires based on three
performance factors: treadwear,