What do the letters and numbers on tires mean?

[OElliott]

The letters and numbers on tires indicate: 1. The first number represents the tire's section width, which is the width of the contact surface between the tire and the road during normal driving; 2. The second number represents the aspect ratio of the tire, and the letter 'R' indicates that the tire is a radial tire; 3. The last number represents the diameter of the wheel rim. Tires are one of the important components of a vehicle, directly contacting the road surface and working together with the vehicle's suspension to absorb shocks during driving, ensuring good ride comfort and smooth driving performance, maintaining excellent traction between the wheels and the road, and improving the vehicle's traction, braking, and off-road capability.

[OAutumn]

Having driven for over a decade, I can tell you those letters and numbers on tires are like their ID cards – all the key information is there. Take P215/65R15 95H for example: The P stands for Passenger, meaning this tire is for passenger vehicles. 215 indicates the tread width in millimeters – wider means more stability. 65 is the aspect ratio (height-to-width percentage), with lower ratios giving flatter tires and better handling. R denotes Radial construction, which is nearly universal now for durability and performance. 15 is the rim diameter in inches, telling you which wheel size it fits. The 95 is the load index (95 = ~690 kg capacity) – watch this when carrying heavy loads. H is the speed rating (max 210 km/h), though safety always comes first. Always cross-check these markings with your vehicle manual to avoid improper installation affecting balance/safety. A 4-digit DOT code like 3519 means the tire was manufactured in the 35th week of 2019 – replace aged tires promptly to prevent blowouts.

[LeArya]

When I first started learning to drive, I was completely baffled by the symbols on the side of tires. Later, I figured out they mainly indicate size and performance specifications. For example, 195/55R16 88V: 195 means the tire width is 195 millimeters, 55 is the aspect ratio of 55%, R stands for Radial tire type, and 16 inches is the rim size. 88 is the load index, meaning it can safely carry about 560 kilograms. V is the speed rating, indicating a maximum speed of 240 km/h, suitable for highways. Additionally, letter combinations like 'TUBELESS' indicate tubeless tires, and 'M+S' stands for mud and snow performance certification, offering better traction in rainy conditions. Understanding these details helps in choosing the right tire model when buying new ones, avoiding unnecessary expenses. Beginners often overlook the load index; overloading accelerates tire wear and increases accident risks, so matching the specifications in the manual is a basic principle. Regularly checking these markings can extend tire life—inspecting wear conditions every six months or so helps maintain smooth driving.

[BenjaminRose]

I can understand the codes on tires at a glance. For example, 225/50R17 98W: 225 is the tire width, 50 is the aspect ratio, R stands for radial tires which are now mainstream and durable, and 17 is the rim size in inches. 98 indicates a load capacity of around 750 kg, and W is the speed rating for 270 km/h. Experienced drivers pay attention to these details to ensure the tires match the vehicle's original specifications, as mismatched or overused tires can lead to poor handling or even blowouts. The manufacturing date is indicated by the last four digits after DOT, such as 0219 meaning the tire was produced in the 2nd week of 2019. Old tires should be replaced to avoid dangerous skidding in rainy conditions. When choosing tires, remember that the correct size is crucial for safety—don’t compromise by buying the wrong ones to save money.