Tire Labeling
Federal law requires tire manufacturers to place standardized information on
the sidewall of
all tires. This information identifies and describes the fundamental
characteristics of the tire
and also provides a tire identification number for safety standard certification
and in case of
a recall.
Information on Passenger Vehicle Tires
Please refer to the diagram below.
1. TIN: U.S. DOT tire identification number.
2. Passenger car tire.
3. Nominal width of tire in millimeters.
4. Ratio of height to width (aspect ratio).
5. Radial.
6. Rim diameter code.
7. Load index & speed symbol.
8. Severe snow conditions.
9. Tire ply composition and materials used.
10. Max. load rating.
11. Tread wear, traction and temperature grades.
12. Max. permissible inflation pressure.
13. SAFETY WARNING.
P215/65R15 95H is an example of a tire size and load index rating. Here is an
explanation
of the various components of that tire size and load index rating. Note that the
tire size and
load index rating may be different from the example.
P
Indicates a tire that may be installed on cars, SUVs, minivans and light
trucks as designated
by the Tire and Rim Association (T&RA).
NOTE:
If your tire size does not begin with a letter this may mean it is designated by
either ETRTO
(European Tire and Rim Technical Organization) or JATMA (Japan Tire
Manufacturing Association).
215
“215” is the nominal width of the tire in millimeters. This three-digit
number gives the
width in millimeters of the tire from sidewall edge to sidewall edge. In
general, the larger
the number, the wider the tire.
65
“65” is the aspect ratio. This two-digit number indicates the tire's ratio of height to width.
R
“R” is the tire construction symbol. R indicates “Radial ply construction”.
15
“15” is the wheel rim diameter in inches.
95
“95” is the Load Index. This two-or three-digit number indicates how much
weight each
tire can support.
H
“H” is the speed rating. The speed rating denotes the maximum speed for which
the use of
the tire is rated.
* For tires with a maximum speed capability over 149 mph, tire manufacturers sometimes use the letters ZR. For tires with a maximum speed capability over 186 mph, tire manufacturers always use the letters ZR.
M+S or M/S: Mud and Snow
AT: All Terrain.
AS: All Season. The “M+S” or “M/S” indicates that the tire has some functional
use in
mud and snow.
U.S. DOT Tire Identification Number (TIN)
This begins with the letters “DOT” which indicates the tire meets all federal
standards. The
next two numbers or letters are the plant code where it was manufactured, and
the last four
numbers represent the week and year the tire was manufactured. For example, the
numbers
457 means the 45st week of 1997. After 2000 the numbers go to four digits. For
example,
the number 2102 means the 21th week of 2002. The other numbers are marketing
codes
used at the manufacturer's discretion. This information is used to contact
consumers if a tire
defect requires a recall.
Tire Ply Composition and Materials Used
The number of plies indicates the number of layers of rubber-coated fabric in
the tire. In
general, the greater the number of plies, the more weight a tire can support.
Tire
manufacturers also must indicate the tire materials, which include steel, nylon,
polyester,
and other.
Maximum Load Rating
This number indicates the maximum load in kilograms and pounds that can be
carried by
the tire.
Maximum Permissible Inflation Pressure
This number is the greatest amount of air pressure that should ever be put in
the tire under
normal driving conditions.
TreadWear, Traction and Temperature Grades
Tread wear: The tread wear grade is a comparative rating based on the wear
rate of the tire
when tested under controlled conditions on a specified government test course.
For
example, a tire graded 150 would wear one and one-half (1 1/2) times as well on
the
government course as a tire graded 100.
Traction: The traction grades, from highest to lowest are AA, A, B, and C. The
grades
represent the tire's ability to stop on wet pavement as measured under
controlled conditions
on specified government test surfaces of asphalt and concrete. A tire marked C
may have
poor traction performance.
Temperature: The temperature grades are A (the highest), B and C, representing
the tire's
resistance to the generation of heat and its ability to dissipate heat when
tested under
controlled conditions on a specified indoor laboratory test wheel.
Snow Tires
In some heavy snow areas, local governments may require true snow tires,
those with very
deeply cut tread. These tires should only be used in pairs or placed on all four
wheels.
Make sure you purchase snow tires that are the same size and construction type
as the other
tires on your vehicle.
SAFETYWARNING
The following safety warning appears on the tire's sidewall.
SERIOUS INJURY MAY RESULT FROM: - EXPLOSION OF TIRE/RIM ASSEMBLY DUE TO IMPROPER MOUNTINGMATCH TIRE DIAMETER TO RIM DIAMETER; NEVER EXCEED 40 psi (275 kPa) TO SEAT BEADS-ONLY SPECIALLY TRAINED PERSONS SHOULD MOUNT TIRES.
- TIRE FAILURE DUE TO UNDER-INFLATION/OVERLOADING/DAMAGEFOLLOW OWNER'S MANUAL AND PLACARD IN VEHICLE-FREQUENTLY CHECK INFLATION PRESSURE AND INSPECT FOR DAMAGE.
Information on Temporary Tires
Please refer to the diagram below.
1. Temporary tires.
2. Nominal width of tire in millimeters.
3. Ratio of height to width (aspect ratio).
4. Diagonal.
5. Rim diameter code.
6. Load index&speed symbol.
T115/70D 16 90M is an example of a tire size and load index rating. Here is
an explanation
of the various components of that tire size and load index rating. Note that the
tire size and
load index rating may be different from the example.
T
Indicates a tire that may be installed on cars, SUVs, minivans and light
trucks as designated
by the Tire and Rim Association (T&RA).
115
“115” is the nominal width of the tire in millimeters. This three-digit
number gives the
width in millimeters of the tire from sidewall edge to sidewall edge. In
general, the larger
the number, the wider the tire.
70
“70” is the aspect ratio. This two-digit number indicates the tire's ratio of height to width.
D
“D” is the tire construction symbol. D indicates “diagonal ply construction”.
16
“16” is the wheel rim diameter in inches.
90
“90” is the Load Index. This two-or three-digit number indicates how much
weight each
tire can support.
M
“M” is the speed rating. The speed rating denotes the maximum speed for which
the use of
the tire is rated.
Letter Rating | Speed Rating |
M | 81 mph |
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