Each tire, in its specification models are followed by numbers and letters of a group of mixed numbers, such as: 185 / 70R1388H, 185R1490S, etc., of which the "88H" and "90S" is the tire carrying mass And speed levels. "88,90" is the load code, "H, S" is the speed level code.
Because each tire in the production process, are strictly in accordance with the fixed technical indicators of the tire design and production, so it contains the quality and speed levels have their critical limit. In the design and production process not only to consider each part of the rubber compound formula, but also consider the tread pattern and the depth of the pattern, the crown and the sidewall of the materials and layers, but also consider the heating, cooling and other complex factors . Therefore, the tire on the marked load quality and speed of the tire is the highest carrying mass and the highest speed level. In the use of tires, it is best not to exceed its maximum, otherwise, it will reduce the life of the tire, a serious occurrence of a vicious tire overturn accident.