What Do the Numbers on Tires Mean?

[OGia]

Tire model such as: 225/60-R17-99H, 225 represents the section width, simply understood as the width of the tire tread. 60 represents the aspect ratio, simply understood as the height of the tire sidewall. R represents the tire type code, where R stands for radial tire. 17 represents the rim diameter, indicating that the tire is suitable for 17-inch rims. 99 represents the load index of the tire, which is the maximum weight the tire can bear. A load index of 99 means the tire can bear a maximum weight of 775KG. H represents the speed rating of the tire, which is the maximum speed the tire can handle. A speed rating of H means the tire can handle speeds up to 210KM/H. Additional information: 1. Tire specifications: Car tire specifications are commonly represented by a set of numbers, where the first number indicates the tire section width, and the second indicates the rim diameter, in inches. 2. For example, 210/50R18 means a tire width of 210 millimeters, an aspect ratio of 50, and a rim diameter of 18 inches. The letters or symbols in the middle have special meanings: "X" indicates a high-pressure tire; "R" and "Z" indicate radial tires; "-" indicates a low-pressure tire.

[VanFaith]

As an experienced driver who often helps friends check their cars, I've found that the numbers on the side of the tire, such as 205/55 R16 91V, are quite important. 205 is the tire width in millimeters, 55 represents the height as a percentage of the width, known as the aspect ratio—the lower the number, the thinner the sidewall, which improves handling but increases bumpiness; R stands for radial construction, 16 is the wheel diameter in inches, 91 is the load index corresponding to 615 kilograms, and V is the speed rating, allowing speeds up to 240 kilometers per hour. Don’t underestimate these details—choosing the wrong size can lead to vehicle instability or increased fuel consumption. I recommend regularly checking tire pressure and keeping it within the range specified in the manual, usually between 2.3 to 2.5 bar, which can extend tire life by thousands of kilometers. When replacing tires, always match the original factory numbers, otherwise the wheels won’t fit, and driving at high speeds becomes even more dangerous. I’ve seen many accidents caused by misreading these numbers, so I always remind car owners to carefully check the manual when changing tires.

[DelAsher]

My family owns several cars, and after driving for twenty years, I'm very familiar with tire numbers. Taking 205/55 R16 as an example, 205 is the width, 55 is the aspect ratio (height proportion), and R16 is the rim size in inches. There are also combinations like 91H, where 91 indicates a load capacity of 615 kilograms, and H represents a maximum speed of 210 km/h. This is crucial because if you choose a tire with a lower speed rating, say only up to 150 km/h, it can easily overheat, wear out, or even blow out at high speeds. I recommend selecting tires based on actual needs for daily use—you can go a grade lower for city driving but don’t skimp too much. Additionally, incorrect sizing affects balance: too high a sidewall makes cornering unstable, while too low increases the risk of blowouts. Regularly check the tire numbers to ensure they match, and don’t wait until they’re worn out to replace them. Checking tire pressure and wear once a year can save you a lot of money and trouble. When it comes to safety, these numbers indirectly affect braking distance and handling, so you can’t afford to be careless.

[SimonLynn]

As an experienced car owner who recently changed tires, let me explain the numbers like 225/45 R18 95W: 225 is the width in millimeters, 45 is the aspect ratio (height to width), R18 is the rim diameter in inches, 95 is the load index (690 kg), and W is the speed rating (270 km/h). Simply put, the size determines if it fits your car, the aspect ratio affects ride comfort (higher ratio means less vibration at speed). Load and speed ratings ensure the tire won't fail under stress. I recommend checking your vehicle manual or using online tools to match specs, and having professionals verify compatibility when changing tires. Wrong numbers may cause rapid wear or higher fuel consumption - pay attention during daily driving.

[StJason]

I've researched money-saving methods, and tire numbers are key. For example, 215/60 R16 98T: 215 is the width in millimeters, 60 is the aspect ratio (height to width proportion), which affects fuel consumption. Lower aspect ratios save fuel but are more prone to damage, while higher ones offer comfort at the cost of more fuel. R16 is the rim size—choosing the wrong size means spending money on something that won't fit. 98 indicates a load capacity of 750 kg, and T means a speed rating of 190 km/h. Selecting a rating too high wastes money, while too low leads to frequent repairs. I recommend matching the original specifications to avoid extra wear from size deviations and ensuring proper tire pressure to extend lifespan. When checking the numbers, also look for the production date code like 2423, meaning the tire was made in the 24th week of 2023, to avoid spending on aged stock tires that may degrade.