What Do the Letters on Tires Represent in Terms of Speed Rating?
2 Answers
Different tires display letters on their sidewalls to indicate their speed rating, which denotes the maximum speed at which the tire can carry a specified load under defined conditions. Below is an introduction to the speed ratings of tires: 1. The letter J on a tire represents 100 km/h, K stands for 110 km/h, L for 120 km/h, M for 130 km/h, N for 140 km/h, P for 150 km/h, Q for 160 km/h, R for 170 km/h, and S for 180 km/h. Additionally, T, U, H, V, and Y represent 190 km/h, 200 km/h, 210 km/h, 240 km/h, and 270 km/h, respectively. ZR indicates speeds exceeding 240 km/h. 2. According to tire specifications, the speed rating indicates the maximum speed at which the tire can carry a specified load under defined conditions. Letters from A to Z represent certified speed ratings ranging from 4.8 km/h to 300 km/h. In recent regulations aimed at standardizing tire labeling, all speed ratings except the continuously variable Z speed rating include both a speed symbol and a load index in their usage instructions.
I've been driving for over a decade. The letters on the side of tires represent speed ratings, simply put, the maximum speed a tire can safely handle. For example, the letter H corresponds to 210 km/h, V is 240 km/h. The later the letter appears in the alphabet, the higher the speed rating, like Y which stands for 300 km/h. I didn't pay attention to this when buying tires before, opting for cheaper ones with lower ratings. As a result, the tires overheated and deformed when accelerating on the highway, almost causing a loss of control. Since then, I've always carefully checked tire specifications, such as looking at labels like 195/65R15 91H, where H is the speed symbol. Choosing tires should match your driving habits; if you frequently drive long distances on highways, opting for higher-rated tires is safer. Additionally, consider both the speed rating and load index together, don't overlook overall performance. Tire aging or improper tire pressure can also affect safety, so regularly check the letter markings during maintenance.
