CHEVROLET 2011 Aveo - Manual (Page 247)

Black plate (45,1) Chevrolet Aveo Owner Manual - 2011
Vehicle Care 10-45
Tire Designations
Tire Size
The following illustration shows
an example of a typical
passenger car 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 : A two‐digit
number that indicates the tire
height‐to‐width measurements.
For example, if the tire size
aspect ratio is 70, as shown in
item C of the illustration, it would
mean that the tire's sidewall is
70% as high as it is wide.
(D) 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.
(E) Rim Diameter : Diameter of
the wheel in inches.
(F) 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 psi (pounds per
square inch) or kPa (kilopascal).