Tire Designations; Tire Terminology And Definitions - Chevrolet Equinox2011 Owner's Manual

10-46 Vehicle Care

Tire Designations

Tire Size
The following is 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.
(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
I n f o r ma t i o n P r o v i d e d b y :
A two digit 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
A
:
of air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in psi (pounds per
square inch) or kPa (kilopascal).
Accessory Weight
combined weight of optional
accessories. Some examples
of optional accessories are,
Diameter of
:
automatic transmission, power
steering, power brakes, power
windows, power seats, and air
These
:
conditioning.
Aspect Ratio
of a tire's height to its width.
The amount
:
The
:
The relationship
: