What Do the Symbols on Tires Mean?
2 Answers
Tire symbols primarily indicate the specifications and performance of the tire. Below is a detailed explanation of the meanings of these markings: 1. The first three digits: The first three digits represent the width of the rubber tire in millimeters. 2. The fourth and fifth digits: The fourth and fifth digits indicate the aspect ratio (also known as the 'profile') of the rubber tire. The aspect ratio refers to the ratio of the tire's cross-sectional height to its width, expressed in '%'. 3. The sixth letter: The sixth letter represents the structural type of the rubber tire. 4. The seventh and eighth digits: The seventh and eighth digits indicate the nominal inner diameter of the rubber tire in millimeters.
At first, I also found the symbols on tires confusing, but gradually I understood them. For example, the string P215/65R15: P stands for passenger car tire type, 215 is the tire width of 215 millimeters, 65 is the aspect ratio indicating the height is 65% of the width, R refers to the radial structure of the tire's internal construction, and 15 is the rim diameter of 15 inches, which must match your wheel. Letters like H or V at the end indicate the speed rating, representing the maximum tolerable speed—for example, H is 210 km/h; exceeding this speed may cause a blowout. The load index number corresponds to a chart showing the weight in kilograms to ensure you don't overload. Later, I also learned to read the DOT code, such as 2318, which means the tire was produced in the 23rd week of 2018. Old tires are prone to cracking and need replacement. Knowing these details gives me more confidence when choosing tires and helps reduce safety risks, especially before the rainy season when an extra check is crucial. Regularly checking wear ratings, like the Treadwear value—higher numbers mean longer durability—shows that these symbols aren't just numbers; they're the foundation of driving safety and require careful attention.
