What does 91w mean on a tire?

[JosephineRose]

Tire 91w refers to the tire's specifications, where 91 specifically indicates that the tire's load capacity is 615 kilograms, and w denotes that the tire's maximum speed is 270 kilometers per hour. Tires are rolling objects mounted on various vehicles or machinery that come into contact with the ground. They are often used under complex and demanding conditions, enduring various deformations, loads, forces, and high and low temperatures during operation. Therefore, they must possess high load-bearing performance, traction performance, and cushioning performance. Tires can be categorized by their intended use into: passenger car tires, light truck tires, construction machinery tires, off-road vehicle tires, and agricultural and forestry machinery tires.