What do the numbers on a tire mean?
2 Answers
Tire numbers represent tire specifications. Here is a partial introduction about tire specifications: 1. Tire specifications are the marking data of a tire's geometric parameters and physical performance. 2. Tire specifications are commonly represented by a set of numbers, where the first number indicates the tire section width, and the second number indicates the tire diameter, both measured in inches. 3. The letters or symbols in the middle of the tire specifications have special meanings: "X" indicates a high-pressure tire; "R" and "Z" indicate radial tires. 4. The numbers before these letters represent the tire's ply rating: The ply rating refers to the nominal number of layers of cord fabric in the tire rubber layer, which does not completely match the actual number of cord layers, but is an important indicator of the tire's strength.
I've been driving for almost 20 years, and the numbers on tires may look complicated but actually follow a logic. Take the common P215/65R15 as an example: P stands for passenger vehicle tire type, 215 refers to the tire width of 215 millimeters, 65 is the aspect ratio meaning the height is 65% of the width, R indicates a radial structure which makes the tire more durable, and 15 is the rim diameter of 15 inches. These numbers not only guide you in choosing new tires but also warn that mismatched tires can cause instability or increased fuel consumption. There are also load index and speed rating symbols at the end, such as 91V indicating a maximum load of 615 kilograms and V representing a top speed of 240 km/h. Getting these wrong can lead to accidents at high speeds. I always remind my friends to check the original specifications when replacing tires and not to buy the wrong model just to save money. Regularly checking tire tread and pressure can extend tire life and save on insurance costs.
