Tire sidewall labeling
 OMV093039L |
This information identifies and describes the fundamental characteristics of the tire and also provides the tire identification number (TIN) for safety standard certification. The TIN can be used to identify the tire in case of a recall.
1. Manufacturer or brand name
Manufacturer or brand name is shown.
2. Tire size designation
A tire's sidewall is marked with a tire size designation. You will need this information when selecting replacement tires for your vehicle.
Example tire size designation:
(These numbers are provided as an example only.)
|
P275/50 R20 113V |
|
|---|---|
|
275 |
Tire width in millimeters. |
|
50 |
Aspect ratio. The tire's section height as a percentage of its width. |
|
R |
Tire construction code (Radial). |
|
20 |
Rim diameter in inches. |
|
113 |
Load Index, a numerical code associated with the maximum load the tire can carry. |
|
V |
Speed Rating Symbol. See the speed rating chart in this section for additional information. |
Wheels are also marked with important information that you need if you ever have to replace one. The following explains what the letters and numbers in the wheel size designation mean.
Example wheel size designation:
|
8.0J X 20 |
|
|---|---|
|
8.0 |
Rim width in inches. |
|
J |
Rim contour designation. |
|
20 |
Rim diameter in inches. |
The chart below lists many of the different speed ratings currently being used for passenger car tires. The speed rating is part of the tire size designation on the sidewall of the tire. This symbol corresponds to that tire's designed maximum safe operating speed.
|
Speed Rating Symbol |
Maximum Speed |
|---|---|
|
S |
180 km/h (112 mph) |
|
T |
190 km/h (118 mph) |
|
H |
210 km/h (130 mph) |
|
V |
240 km/h (149 mph) |
|
W |
270 km/h (168 mph) |
|
Y |
300 km/h (186 mph) |
3. Checking tire life (TIN: Tire Identification Number)
Any tires that are over 6 years old, based on the manufacturing date, should be replaced by new ones. You can find the manufacturing date on the tire sidewall, displaying the DOT Code. The manufacturing date is designated by the last four digits (characters) of the DOT code.
DOT: XXXX XXXX OOOO
The front part of the DOT means a plant code number, tire size and tread pattern and the last four numbers indicate week and year manufactured.
For example, DOT XXXX XXXX 1624 represents that the tire was produced in the 16th week of 2024.
Tires degrade over time, even when they are not being used. Regardless of the remaining tread, we recommend that tires be replaced after approximately 6 years of normal service. Heat caused by hot climates or frequent high loading conditions can accelerate the aging process. Failure to follow this warning can result in sudden tire failure, which could lead to a loss of control and an accident involving serious injury or death.
4. Tire ply composition and material
The number of layers or plies of rubber-coated fabric in the tire. Tire manufacturers also must indicate the materials in the tire, which include steel, nylon, polyester, and others. 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.
5. Maximum permissible inflation pressure
This number is the greatest amount of air pressure that should be put in the tire. Do not exceed the maximum permissible inflation pressure. Refer to Vehicle certification label/tire specification and pressure label .
6. Maximum load rating
This number indicates the maximum load in kilograms and pounds that can be carried by the tire. When replacing the tires on the vehicle, always use a tire that has the same load rating as the factory installed tire.
7. Uniform tire quality grading
Quality grades can be found where applicable on the tire sidewall between tread shoulder and maximum section width.
For example:
TREADWEAR 200
TRACTION AA
TEMPERATURE A
-
The traction grade assigned to this tire is based on straight ahead braking traction tests, and does not include acceleration, cornering, hydroplaning, or peak traction characteristics.
-
The temperature grade for this tire is established for a tire that is properly inflated and not overloaded. Excessive speed, under inflation, or excessive loading, either separately or in combination, can cause heat build-up in tire and sudden tire failure. This can cause loss of vehicle control and serious injury or death.
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-a-half times (1½) 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 may depart significantly from the norm due to variations in driving habits, service practices and differences in road characteristics and climate.
The tires available as standard or optional equipment on your vehicle may vary with respect to grade.
The traction grades, from highest to lowest, are AA, A, B and C. Those 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.
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.
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. Grades B and A represent higher levels of performance on the laboratory test wheel than the minimum required by law.
