When you see a marking like 81Y on a tire’s sidewall, it tells you two important things about the tire’s capability — its load index and speed rating.

Load Index 81: This number indicates how much weight the tire can safely carry. A This load index means the tire can handle up to 462 kg (1019 lbs) per tire when properly inflated.

Speed Rating Y: The letter shows the maximum speed the tire can safely sustain. It is designed to safely reach speeds of up to 300 km/h (186 mph).