How is the speed rating classification for car tires divided?

[StCalvin]

Letters on car tires represent speed ratings, denoted by E, F, G, J, K, L, M, N, P, Q, S, T, U, H, V, W, Y, and Z. Each letter corresponds to a different speed grade. Below are the maximum driving speeds represented by these letters: 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 240, 270, and 300 kilometers per hour, respectively. The higher the speed rating of a tire, the greater the maximum speed it can withstand, and the stronger the tire's grip during driving. However, tires with higher speed ratings tend to have poorer wear resistance. This is because higher-speed-rated tires use softer materials, resulting in a gradually shortened service life.