How to Read Tire Size?
2 Answers
On the sidewall of the tire, there is a display. The first three digits shown on the tire sidewall, such as 245, 275, etc., indicate the relevant size of the tire. When replacing tires, it is essential to use tires of the same size as the original vehicle to ensure proper tire usage and maintain the stability of the motor vehicle's operation. Below are some precautions regarding tire purchase and usage: 1. When purchasing tires, always check the production date: Avoid buying tires with production dates that are too old. Tires are rubber products and will age even if unused. 2. During regular vehicle use, frequently inspect tire pressure and check for any damage on the tire surface: The sidewall of the tire is relatively fragile, and if it is cut or punctured, it cannot be repaired. It is recommended that owners replace their tires every four years, even if the mileage driven within those four years is minimal.
I understand tire sizes mainly by decoding the markings on the sidewall. When changing tires in the garage myself, I pay attention to those combinations of numbers and letters, such as 225/65R17. The first three digits, 225, represent the tire width in millimeters—the larger the number, the wider the tire, which provides better stability at high speeds but consumes more fuel. The following number, 65, is the aspect ratio percentage—the higher it is, the more comfortable the ride with less bumpiness. The 'R' stands for radial construction, which is common for tires. The 17 indicates the rim size in inches, and changing wheels must match this size. Too large a rim may cause rubbing against the inner fender, while too small a rim can lead to unstable braking. I recommend glancing at the sidewall codes before driving and cross-checking with the recommended size on the door pillar, especially when using winter tires in rain or snow—smaller sizes are safer. Regular maintenance should also include checking tire pressure and wear, as incorrect sizes can lead to a sharp increase in fuel consumption or the risk of a blowout.
