What does 91v mean on a tyer?

The "91V" on a tire indicates its load index and speed rating. The "91" is the load index, which specifies the maximum load the tire can safely carry, in this case, 615 kg (1,356 lbs). The "V" denotes the speed rating, indicating that the tire is rated for speeds up to 240 km/h (149 mph). Together, these markings provide essential information about the tire's performance capabilities.