Understanding Tire Marking Labels
International Tire Approval Marks
Tire and Loading Information Label
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 the tire identification number (TIN) for safety standard certification and in case of a recall.
See Understanding Tire Marking Labels for label explainations.
P indicates that the tire is for passenger vehicles. HL indicates that the tire is a high-load rated tire.
This three-digit number gives the width in millimeters of the tire from sidewall edge to sidewall edge. Therefore, if a tire is marked P245/35R21, then the tire width is 245 mm.
This two-digit number, also known as the profile, gives the sidewall height as a percentage of the tire width. For example, if the tire width is 245 mm, and the aspect ratio is 35, then the sidewall height will be 85.75 mm.
R indicates that the tire is of Radial ply construction. Therefore, if a tire is marked P245/35R21, then R is the Radial ply construction.
This two-digit number is the diameter of the wheel rim in inches. So, if a tire is marked P245/35R21, then the wheel diameter is 21 inches.
This two- or three-digit number is the tire's load index. It is a measurement of how much weight each tire can support. This number is not always shown.
The speed rating, when stated, denotes the maximum speed at which the tire should be used for extended periods. The ratings range from 99 mph (160 kmph) to 186 mph (300 kmph). These ratings are listed in the following table.
| Rating | Speed (mph) | Speed (kmph) |
|---|---|---|
| Q | 99 | 160 |
| R | 106 | 170 |
| S | 112 | 180 |
| T | 118 | 190 |
| U | 124 | 200 |
| H | 130 | 210 |
| V | 149 | 240 |
| W | 168 | 270 |
| Y | 186 | 300 |
Regulations require that the TIN begins with the letters DOT and is followed by two numbers or letters that indicate where it was manufactured. The last four numbers represent the week and year the tire was built. For example, the number 1706 means the 17th week of 2006. The other numbers are marketing codes used at the manufacturer's discretion. This information can be used to contact consumers if a tire defect requires a recall.
Maximum permissible inflation pressure means the maximum cold inflation pressure in which a tire may be inflated to. The tire pressure must be at or below this pressure when the tire is cold, but it is okay for the it to exceed this value when it is warmed up.
This number indicates the tire's wear rate. See Uniform Tire Quality Grading.
This letter indicates a tire's ability to stop on wet pavement. See Uniform Tire Quality Grading.
This letter indicates a tire's heat resistance grading. See Uniform Tire Quality Grading.
The number of plies in both the tread and sidewall area indicates how many layers of rubber-coated material make up the structure of the tire. Information is also provided on the type of materials used.
This is the maximum load that can be carried by the tire.
Tire manufacturers must test and certify that all applicable safety and performance standards are met before any tires can be sold in countries. This can include sidewall branding, durability, physical dimensions, high-speed endurance, road noise, and wet traction.
Many tires are globally sold, so tires may be branded with multiple approval codes from various countries.
 | United States Department of Transportation (DOT) |
 | China Compulsory Certification (CCC) Mark This is the China Compulsory Certification mark for products being exported to or sold in the People's Republic of China. |
 | United Nations Economic Commission of Europe (U.N.E.C.E.) |
The symbol identifying the United Nations Economic Commission for Europe (U.N.E.C.E., sometimes referred to as E.C.E.), is found on a tire's sidewall. The symbol certifies that the tire manufacturer meets all regulations, including the load index and speed symbol appearing in its service description.
The letter E or e and number code (in a circle or rectangle), identifies the country where the tire was originally registered. The next two digits (the Regulation Series), indicate where the tire was approved (such as 02 for E.C.E. Regulation 30 governing passenger tires). The last digits depict the E.C.E. mark, type-approval numbers.
Tested tires meeting the pass-by noise and wet traction limits may have another E.C.E. branding followed by an -s and w (for sound and wet traction, respectively). One or two E.C.E. symbols may also appear on the tire's sidewall.
The following information relates to the tire grading system developed by the National Highway Traffic Safety Administration (NHTSA), which grades tires by tread wear, traction, and temperature performance.
Quality grades, where applicable, can be found on the tire sidewall between the tread shoulder and maximum section width. For example:
| TREADWEAR 180 | TRACTION AA | TEMPERATURE A |
Passenger car tires must also conform to Federal Safety Requirements in addition to the marking requirements.
The treadwear 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 as well on a government test course as a tire graded 100. The relative performance of tires depends on the actual conditions of their use, however, and may significantly depart from the norm due to variations in driving habits, service practices, and differences in both road characteristics and climate.
The traction grades (from highest to lowest) are: AA, A, B, and C. These grades represent a tire’s ability to stop on a 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. These represent 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.
The grade C corresponds to a level of performance that all passenger car tires must meet under the Federal Motor Safety Standard No. 109.
Grades B and A represent higher levels of performance on the laboratory test wheel than the minimum required by law.
The stated tire pressures provide the optimum vehicle ride and handling characteristics for all normal operating conditions.