Black plate (46,1)
Cadillac SRX Owner Manual (GMNA-Localizing-U.S./Canada/Mexico-
6081464) - 2014 - CRC - 10/4/13
10-46
Vehicle Care
(7) 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 is an example of a
typical passenger vehicle
tire size.
(1) 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.
(2) Tire Width
:
The three-digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(3) 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 3 of the illustration, it would
mean that the tire's sidewall is
60 percent as high as it is wide.
(4) 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.
(5) Rim Diameter
:
Diameter of
the wheel in inches.
(6) Service Description
:
These characters represent the
load index and speed rating of
the tire. The load index
represents the load carrying
capacity a tire is certified to
carry. The speed rating is the
maximum speed a tire is
certified to carry a load.
Tire Terminology and
Definitions
Air Pressure
:
The amount of
air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).