How to Interpret Tire Specification Parameters?
3 Answers
Tire model specifications can be found on the sidewall (tread pattern model). The tire specification size is expressed in millimeters as the section width and the percentage of the aspect ratio. This is followed by: tire type code, rim diameter (in inches), load index (allowable load mass code), and allowable vehicle speed code. The influence of tire specifications on other indices is as follows: 1. The width of the tire is an important index affecting the vehicle's fuel consumption and economic performance. The wider the tire, the larger the contact area with the ground, and the corresponding fuel consumption increases. 2. Aspect ratio: The lower the aspect ratio of a car tire, the greater the pressure it can withstand, the higher the responsiveness, making it very quick to handle, but it requires a high level of elasticity and softness from the shock absorbers.
Every time I check the tire parameters, I squat down to carefully examine the sidewall of the tire, where there’s a string of numbers and letters like a code, such as 205/55 R16 91V. The 205 represents the tire width of 205 millimeters—the larger the number, the wider the tire. The 55 is the aspect ratio, meaning the tire’s height is 55% of its width. The R stands for radial construction, which is pretty much standard nowadays. The 16 indicates the rim size of 16 inches. In the 91V, the 91 is the load index, capable of supporting 615 kilograms, and the V is the speed rating, with a maximum speed of 240 km/h. These parameters must match the original specifications of the car; otherwise, they can affect handling and damage the suspension. When changing tires, you also need to look for the last four digits of the DOT code—for example, 1823 means the tire was manufactured in the 18th week of 2023.
The tire specifications are engraved on the sidewall. Let me teach you how to read them: Take the parameters like 215/60 R17 for example. The 215mm tire width determines the grip level, while the 60% aspect ratio controls the tire thickness—the higher the number, the softer the suspension. The 'R' stands for radial tire construction, and the 17-inch size must match the corresponding wheel rim. When changing tires, also check the alphanumeric combination at the end, such as 98H for load index and speed rating—'H' indicates a maximum speed of 210 km/h. Additionally, the production date is hidden in the last four digits of the DOT code; for instance, 2321 means the tire was produced in the 23rd week of 2021. Be careful not to recklessly alter specifications to save money—a diameter difference exceeding 3% is beyond the safe range.
