What do the letters on tires mean?
3 Answers
Taking 225/60-R17-99H as an example, the meanings of the numbers and letters in the tire model are as follows: 1. 225: Represents the section width, simply understood as the width of the tire tread. 2. 60: Represents the aspect ratio, simply understood as the height of the tire sidewall. 3. R: Represents the tire type code, where R stands for radial tire. 4. 17: Represents the rim diameter, indicating the tire is suitable for 17-inch rims. 5. 99: Represents the load index of the tire, which is the maximum weight the tire can bear. 99 corresponds to a maximum load capacity of 775KG. 6. H: Represents the speed rating of the tire, which is the maximum speed the tire can withstand. H corresponds to a maximum speed of 210KM/H.
I've been driving for decades, and those letters on tires indeed have specific meanings. Take the common P215/65R15 95H as an example: 'P' stands for passenger vehicle tires, suitable for regular sedans or SUVs. '215' is the tire width in millimeters – the larger the number, the wider the tire, providing better stability. '65' is the aspect ratio, meaning the tire's height is 65% of its width. A smaller number indicates a flatter tire, enhancing handling but slightly reducing comfort, while a larger number has the opposite effect. 'R' denotes radial construction, which is the design used by most tires today. '15' is the rim diameter in inches, matching your vehicle's wheel size. The '95' that follows is the load index, representing the maximum weight each tire can bear (checking the chart shows 670 kg). 'H' is the speed rating, corresponding to a maximum speed of 210 km/h. I remember once when I changed tires without paying attention to the load index, overloading caused dangerous tire bulging. So, I strongly recommend always selecting tires according to your car's manual – don't underestimate these letters, as they directly impact driving safety and fuel efficiency. For winter or snow tires, also look for additional snowflake symbols or M+S markings to ensure they're suitable for weather changes.
As a friend who often drives, I was initially confused by the letters on tires. For example, a tire marked 225/55R17 98T. '225' is the width in millimeters, which affects grip during turns—wider tires are more stable but consume more fuel. '55' is the aspect ratio; a smaller ratio makes the tire look cooler but reduces cushioning. 'R' stands for radial, a durable structure commonly used today. '17' is the rim size in inches, which must match your original vehicle. The '98' that follows is the load index, corresponding to 750 kg per tire. 'T' is the speed rating, indicating a maximum of 190 km/h. I remember when I first changed tires, I asked the mechanic why these numbers were on the label, and he explained that a speed rating too low could cause shaking at high speeds. For daily driving, it's not just about size; you also need to regularly check the wear indicators, as shallow treads can lead to skidding. In rain or snow, tires with 'Aqua' or snowflake symbols offer better safety performance.
