What does DOT on tires mean?

[DeKai]

Tire DOT refers to the certification by the U.S. Department of Transportation, usually followed by a series of numbers and letters, which respectively indicate the tire's origin information and factory code. The last four digits represent the tire's production date. Tires are circular elastic rubber products mounted on metal rims, designed for rolling contact with the ground on various vehicles or machinery. They support the vehicle body, absorb external shocks, ensure contact with the road surface, and maintain driving performance. Tires operate under complex and demanding conditions, enduring various deformations, load forces, and high and low temperatures during use, while providing high load-bearing capacity, traction performance, and cushioning ability.