The marking “115T” found on a tire sidewall indicates its load index and speed rating. The “115” represents the load index, a numerical code that specifies the maximum weight a single tire can carry when properly inflated. A load index of 115 corresponds to a load-carrying capacity of 2679 pounds (1215 kg). The “T” signifies the speed rating, which denotes the maximum speed at which the tire is certified to carry a load corresponding to its load index. A “T” speed rating means the tire is approved for speeds up to 118 mph (190 km/h).
Understanding these ratings is crucial for vehicle safety and performance. Using tires with an insufficient load index can lead to tire failure, particularly when carrying heavy loads or during demanding driving conditions. Exceeding the designated speed rating can also result in tire damage and increases the risk of accidents. Tire manufacturers establish these standards through rigorous testing to ensure reliability and safety for vehicle occupants. Matching or exceeding the original equipment manufacturer (OEM) specifications for load index and speed rating is advisable when replacing tires.
