120 refers to the tread width of the tire in millimeters, 70 refers to the tire height of 70 millimeters, and 12 refers to the diameter of the rim. Tire: A tire is an elastic rubber product in the shape of a circular ring that is assembled on various vehicles or machinery to roll on the ground. It is usually mounted on a metal rim, supports the vehicle body, cushions external impacts, ensures contact with the road surface, and guarantees the vehicle's driving performance. Tires are often used under complex and demanding conditions, enduring various deformations, loads, forces, and high and low temperatures during operation. Therefore, they must possess high load-bearing capacity, traction performance, and cushioning performance. At the same time, they are required to have high wear resistance and flex resistance, as well as low rolling resistance and heat generation. Half of the world's rubber consumption is used for tire production, highlighting the significant demand for rubber in tires. Introduction to Tire Models: Tire model markings mostly appear as: 215/70R15. The meanings of these numbers are as follows: 215 represents the tire section width in millimeters, generally ranging between 145—285mm with intervals of 10mm; 70 is the aspect ratio, which is the ratio of the tire sidewall height to the tire section width, where 70 represents 70%. Generally, the aspect ratio of tires ranges between 30%—80%. Under normal circumstances, ordinary cars should not use tires with an aspect ratio > 75%, while luxury cars and high-performance sports cars are recommended to use tires with an aspect ratio < 60%; R is the abbreviation for Radial, indicating that the tire has a radial structure, and 15 is the outer diameter of the rim in inches. If a tire is marked as 6.00—12, it indicates that it is not a radial tire but a bias-ply tire. Such tires are rarely seen on cars today due to their poor safety, load capacity, and high-speed stability, and are only used in some low-end off-road vehicles and heavy-duty trucks.
