GMC Sierra Denali 2006 Owner's Manual page 336

Light Truck (LT-Metric) Tire
(A) Tire Size: The tire size code 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" illustration 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.
5-56
(C) Dual Tire Maximum Load: Maximum load that
can be carried and the maximum pressure needed to
support that load when used in a dual configuration.
For information on recommended tire pressure see
Inflation - Tire Pressure on page 5-61 and Loading Your
Vehicle on page 4-42.
(D) 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.
(E) Tire Identification Number (TIN): The letters and
numbers following DOT code are the Tire Identification
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.
(F) Tire Ply Material: The type of cord and number of
plies in the sidewall and under the tread.
(G) Single Tire Maximum Load: Maximum load that
can be carried and the maximum pressure needed
to support that load when used as a single. For
information on recommended tire pressure see
Inflation - Tire Pressure on page 5-61 and Loading
Your Vehicle on page 4-42.