Tong Jia tire number is located on both sides of the tire, indicating the production number, manufacturer's trademark, size specification, grade, maximum load and corresponding air pressure, Chinese phonetic code of carcass cord fabric, installation requirements and driving direction sign.

The parameters of automobile tire size model are expressed as the percentage of section width and flattening rate, and the unit is millimeter. Add: tire type code, rim diameter (inch), load index (allowable bearing mass code) and allowable speed code. Suppose tyre size is 195/55/R 16 85V.

195- refers to the tire width 195 mm.

55—— refers to the tire flattening rate, that is, the section height is 55% of the width.

R- refers to radial tire (the inner layer of this tire is radial tire).

15- refers to the rim diameter of 15 inch.

85—— The load index 85 represents the maximum bearing capacity of 5 15kg, and the four tires are 5 15×4 = 2060kg.

V- refers to the speed level of 240 km/h.