Meaning of Tire Numbering?
2 Answers
Tire numbering refers to the internationally standardized tire code, typically located on the sidewall of the tire, indicating the section width and aspect ratio percentage, measured in millimeters. It includes the tire type, rim diameter (in inches), followed by the load index and speed rating. Below is a partial introduction to the 3T indices of tires: 1. Treadwear Index (TREADWEAR): Reflects the tire's wear resistance. A higher value indicates greater wear resistance but also means the tire is harder and less comfortable, and vice versa. Generally, a treadwear index between 280-320 is considered moderate, theoretically allowing for approximately 100,000 kilometers of driving. 2. Traction Index (TRACTION): Represents the tire's grip level, with the following letters indicating the strength of traction, ranked from highest to lowest as AA, A, B, and C. 3. Temperature Rating (TEMPERATUREA): Indicates the tire's temperature resistance, with the following letters representing the high-temperature resistance level, ranked from highest to lowest as A, B, and C for passenger car tires.
That string of numbers on the tire, like 205/55R16, is something I often need to know after buying a car. Actually, the first part, 205, refers to the tire width in millimeters. A wider tire makes the car more stable but increases fuel consumption—my old car had 185-width tires, which were fuel-efficient but prone to slipping when cornering. The second part, 55, is the aspect ratio, which is the percentage of the tire's sidewall height relative to its width. A higher ratio means more comfort but worse handling. The letter R stands for radial construction, which most cars use, offering strong durability. The last number, 16, is the rim diameter in inches, and it must match my car's wheel hub; otherwise, the tire won't fit. I once wasted money by getting the wrong diameter when changing tires—it affects acceleration and ride comfort. There are also hidden details like 91H at the end: 91 is the load index (weight capacity), and H is the speed rating, meaning it can handle up to 210 km/h. Speeding on highways can be dangerous, so it's best to choose tires that match the manual's specifications. Understanding these details helps you change tires safely and save money—don’t just focus on price and ignore the parameters, or you might end up spending a fortune on repairs.
