Your tire
has very useful information molded
into the sidewall. It shows the name
of the tire, its size, whether it is
tubeless or tube type, the maximum
load and maximum inflation, the
important safety warning and much
other information.
Passenger Tires
Shown
below is the sidewall of a popular
"P-metric," speed-rated auto tire.
"P" stands for passenger; "215"
represents the width of the tire in
millimeters; "65" is the ratio of
height to width; "R" means radial;
"15" is the nominal rim diameter
code; and "95H" is the optional
service description that consists of
the load index (95) and the speed
symbol (H). Some older speed-rated
tires may include the speed symbol
immediately before the "R" instead
of showing a service description.
Typical
Passenger Tire
A "B" in place of the "R" means the
tire is belted bias construction. A
"D" in place of the "R" means
diagonal bias construction. "M+S"
with the mountain/snowflake symbol
is the designation that the tire
meets the RMA (Rubber Manufacturers
Association) definitions for use in
severe snow conditions.
The
maximum load is shown in kg
(kilograms) and in lbs (pounds), and
maximum pressure in kPa
(kilopascals) and in psi (pounds per
square inch).
The
letters "DOT" certify compliance
with all applicable safety standards
established by the Department of
Transportation (DOT).
Adjacent
to this is a tire identification or
serial number. This serial number is
a code with up to 12 digits that are
a combination of numbers and
letters. The last characters are
numbers identifying the week and
year of manufacture. (Example:
"1501" means fifteenth week of the
year 2001.)
The
sidewall also shows the type of cord
and number of plies in the sidewall
and under the tread.
The DOT
requires tire manufacturers to grade
passenger car tires based on three
performance factors: treadwear,
traction and temperature resistance.
Typical Light Truck Tire
Source: Rubber Manufacturers
Association
