Tires have very useful information molded onto their sidewall. It shows the brand and model name of the tire, its size, whether it is tubeless or tube type, the maximum load and the maximum inflation, safety warning(s), and much more.
LT245/75R16 120/116Q Load Range E – (Light Truck Example) Size marking, service description (load index and speed symbol) and load range for a metric light truck tire. The load range identifies the tire’s load and inflation limits.
Load Index – The load index is a numerical code associated with the maximum load a tire can carry at the speed indicated by its speed symbol under specified service conditions. The load index should not be used independently to determine replacement tire acceptability for load capacity.
Speed Symbol – The speed symbol is also known as a “speed rating.”
Max Load 730 kg (1609 lbs) and 240 kPa (35 psi) Max Pressure Cold – (Passenger Example) indicates maximum load and maximum cold inflation pressure of the tire. Sidewall markings are given in both metric and English units. Follow tire inflation pressure recommendations on the vehicle tire placard, certification label, or in the owner’s manual.
Max Load Single 1380 kg (3042 lbs) at 550 kPa (80 psi) Max Pressure Cold
Max Load Dual 1260 kg (2778 lbs) at 550 kPa (80 psi) Max Pressure Cold – (Light Truck Example) indicates the maximum load of the tire and corresponding maximum cold inflation pressure for that load when used in a single or dual configuration. Sidewall markings are given in both metric and English units. Follow tire inflation pressure recommendations on the vehicle tire placard, certification label, or in the owner’s manual.
DOT MA L9 ABCD 0309 – The “DOT” symbol certifies the tire manufacturer’s compliance with U.S. Department of Transportation (U.S. DOT) tire safety performance standards. Next to these letters is the tire identification number (TIN) – also known as the tire “serial” number. The first two characters are the factory code indicating where the tire was made. The last four digits are numbers identifying the week and year of manufacture (Example: “0309” means third week of the year 2009.) If a tire DOT ends in only three (3) digits, the tire was manufactured before January 2000 and should be removed from service and be scrapped because it is over 10 years old.
Plies/Fabric Information – The ply/fabric information identifies the number of plies and type of cord materials in the tire tread and sidewall areas.
Radial – A tire with a radial construction must show the word “RADIAL” on the sidewall. A radial tire is also indicated by the character “R” in the size designation.
Tubeless – The tire must be marked either “tubeless” or “tube type.”
M + S – This mark is commonly found on “all season” and winter tires. In several formats, the letters “M” and “S” indicate the tire is intended for limited mud and snow service. Other formats include: “MS,” “M/S,” or “M&S.”
Mountain-Snowflake Symbol – This mark is commonly found on winter/snow tires. Tires that meet the RMA definition for passenger and light truck tires for use in severe snow conditions are marked on at least one sidewall with the letters “M” and “S” (as stated above) plus the mountain snowflake symbol.
The speed symbol, also known as a speed rating, indicates the speed category at which the tire can carry a load corresponding to its load index under specified service conditions. Speed ratings are based on laboratory tests that relate to performance on the road, but are not applicable if tires are under inflated, over-loaded, worn out, damaged, or altered.
Although a tire may be speed rated, Cooper Tire does not endorse the operation of any vehicle in an unsafe or unlawful manner. Furthermore, tire speed ratings do not imply that a vehicle can be safely driven at the maximum speed for which the tire is rated, particularly under adverse road and weather conditions or if the vehicle has unusual characteristics.
When replacing tires on a vehicle, it is recommended and preferred that all four tires be replaced at the same time for continued optimal vehicle performance. However, for those cases where this is not feasible, the new tires should always be placed on the rear axle of the vehicle. Generally, new tires with deeper tread will provide better grip and evacuate water more effectively, which is important as a driver approaches hydroplane situations. Placing greater traction on the rear axle on wet surfaces is necessary to prevent possible over-steer condition and possible loss of vehicle control, especially during sudden maneuvers.