Tire Markings
Tire Example
(1) P or LT: The "P" indicates the tire is for passenger vehicles. "LT" indicates the tire is for light trucks.
(2) Nominal Width: This three-digit number gives the width of the tire in millimeters from sidewall edge to sidewall edge. The larger the number, the wider the tire.
(3) Aspect Ratio: This two-digit number gives the tire's ratio of height to width. A number of 50 or lower indicates a short sidewall for improved steering response and better overall handling.
(4) R: The "R" stands for radial. Radial tires have been the industry standard for the past 20 years.
(5) Rim Diameter Code: This two-digit number is the wheel or rim diameter in inches.
(6) Load Index and Speed Symbol: This two or three digit number is the tire's load index. It is an indicator of how much weight each tire can support. The speed rating tells you the maximum speed capability of a tire. The speed ratings include speeds from 99 mph to above 186 mph. Note: You may not find this information on all tires because it is not required by law.
(7) DOT Tire Identification Number: This number begins with the letters "DOT" and indicates that the tire meets all standards. The next two or three numbers or letters are the plant code where the tire was manufactured. The last four numbers represent the week and year the tire was built.
(8) M + S: This indicates that the tire has some mud and snow capability.
(9) Tread Wear Indicators: Tread wear indicator bars are built into the tire tread. These bars are invisible, or barely visible when the tires are new and gradually appear as the tread wears down.
(10) Tire Ply Composition and Materials: This describes the amount of plies and the material that it is composed of.
(11) Treadwear: The treadwear rating indicates how long the tire should last. The higher the number, the longer it should take for the tires to wear down.
(12) Traction: The traction rating indicates the tire's ability to allow a car to stop on wet pavement in a shorter distance.
(13) Temperature: The temperature rating indicates how well the tire resists heat.
(14) Maximum Permissible Inflation Pressure / Maximum Load Rating: This maximum permissible inflation pressure is the greatest amount of air pressure that should ever be put in the tire. This is NOT the same as the vehicle manufacturer's recommended tire pressure. The maximum load rating is a number indicates the maximum load the tire can carry.
(15) Reinforced: Reinforced marking where applicable.
(16) ECE: ECE type approval mark and number.
Max. Load Dual kg (lbs) at kPa (psi) Cold
This information indicates the maximum load and tire pressure when the tire is used as a dual, that is, when four tires are put on each rear axle (a total of six or more tires on the vehicle).
Max. Load Single kg (lbs) at kPa (psi) Cold
This information indicates the maximum load and tire pressure when the tire is used as a single.
Load Range
This information identifies the tire's load-carrying capabilities and its inflation limits.