07 Wheels and tiresTire designations
07172
123456
1211108
7
9
G026442
Federal law mandates that tire manufacturers
place standardized information on the sidewall
of all tires (see the illustration).
The following information is listed on the tire
sidewall:
The tire designation (the following figures are
examples of a tire designation):
215: the width of the tire (in millimeters)
from sidewall edge to sidewall edge. The
larger the number, the wider the tire.65: The ratio of the tire's height to its width.R: Radial tire.15: The diameter of the wheel rim (in
inches).
95: The tire's load index. In this example, a
load index of 95 equals a maximum load of
1521 lbs (690 kg).H: The tire's speed rating, or the maximum
speed at which the tire is designed to be
driven for extended periods of time, carry-
ing a permissible load for the vehicle, and
with correct inflation pressure. For exam-
ple, H indicates a speed rating of 130 mph
(210 km/h).NOTE
This information may not appear on the tire
because it is not required by law.
M+S or M/S = Mud and Snow; AT = All
Terrain;AS = All SeasonU.S. DOT Tire Identification Number (TIN):
This begins with the letters "DOT" and indi-
cates that the tire meets all federal stand-
ards. The next two numbers or letters are
the plant code where it was manufactured,
the next two are the tire size code and the
last four numbers represent the week and
year the tire was built. For example, the
numbers 317 mean the 31st week of 1997.
After 2000 the numbers go to four digits.
For example, 2501 means the 25th week of
2001. The numbers in between are mar-
keting codes used at the manufacturer's
discretion. This information helps a tire
manufacturer identify a tire for safety recall
purposes.Tire Ply Composition and Material Used:
Indicates the number of plies indicates or
the number of layers of rubber-coated fab-
ric in the tire tread and sidewall. Tire man-
ufacturers also must indicate the ply mate-
rials in the tire and the sidewall, which
include steel, nylon, polyester, and others.
07 Wheels and tiresUniform Tire Quality Grading
07176
ALL PASSENGER VEHICLE TIRES MUST
CONFORM TO FEDERAL SAFETY
REQUIREMENTS IN ADDITION TO THESE
GRADES
Quality grades can be found, where appli-
cable, on the tire sidewall between the tread
shoulder and maximum section width. For
example:
Treadwear 200 Traction AA Temperature ATREADWEARThe treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified gov-
ernment test course. For example, a tire gra-
ded 150 would wear one and one half (1 1/2)
times as well on the government course as a
tire graded 100. The relative performance of
tires depends upon the actual conditions of
their use, however, and many depart signifi-
cantly from the norm due to variation in driving
habits, maintenance practices and differences
in road characteristics and climate.TRACTIONThe traction grades, from highest to lowest, are
AA, A, B, and C, as measured under controlled
conditions on specified government test sur-
faces of asphalt and concrete. A tire marked C
may have poor traction performance.
WARNING
The traction grade assigned to this tire is
based on braking (straight-ahead) traction
tests and is not a measure of cornering
(turning) traction.TEMPERATUREThe temperature grades are AA (the highest),
A, B, and C, representing the tire's resistance
to the generation of heat and its ability to dis-
sipate heat when tested under controlled con-
ditions on a specified indoor laboratory test
wheel. Sustained high temperature can cause
the material of the tire to degenerate and
reduce tire life, and excessive temperature can
lead to sudden tire failure. The grade C corre-
sponds to a minimum level of performance that
all passenger vehicle tires must meet under the
Federal Motor Safety Standard No. 109.
Grades B and A represent higher levels of per-
formance on the laboratory test wheel than the
minimum required by law.
WARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, under-
inflation, or excessive loading, either sepa-
rately or in combination, can cause heat
buildup and tire failure.
