What Do the Numbers on Car Tires Mean?

3 Answers
HenryAnn
07/25/25 6:35am
Taking 225/60R1799H as an example, the meanings of the numbers and letters in the tire model are as follows: 1. 225 represents the section width, which can be simply understood as the width of the tire tread. 2. 60 represents the aspect ratio, which can be simply understood as the height of the tire sidewall. 3. R stands for the tire type code, with R indicating a radial tire. 4. 17 represents the rim diameter, meaning the tire is suitable for 17-inch rims. 5. 99 represents the tire's load index, indicating the maximum weight the tire can bear. 6. H stands for the tire's speed rating, indicating the maximum speed the tire can withstand.
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OJack
08/10/25 6:13pm
As a veteran driver with over a decade of experience, I've learned that the numbers on tires are crucial. Take the common code 'P215/65R15 95H' for example: P stands for passenger car type, 215 is the tire width in millimeters, 65 represents the aspect ratio (meaning the height is 65% of the width) - the smaller this number, the flatter the tire and the more stable at high speeds. R indicates radial construction, which is almost universally used nowadays. 15 is the wheel diameter in inches. The load index 95 means it can carry approximately 690 kg, while the speed rating H allows for a maximum speed of 210 km/h. If you recklessly change to tires with incorrect dimensions, your car may feel unstable and consume more fuel. I once bought mismatched tires to save money and ended up skidding during turns. I recommend regularly checking tire pressure to maintain moderate wear, and monthly inspections of the tread wear indicators to ensure safe driving and prevent accidents.
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Brady
08/10/25 6:14pm
I always pay attention to driving safety, as tire numbers are a matter of life and death. Take '205/55R16 91V' for example: the 205 width in millimeters affects grip, a slightly higher 55 aspect ratio provides better anti-slip performance, especially in rain or snow. R stands for radial construction, ensuring stability. The 16-inch wheel diameter is crucial. The 91 load index means a maximum of 690 kg—overloading can lead to tire bursts. The V speed rating of 240 km/h is risky for speeding, which may cause accidents. Mismatched numbers can lead to bumpy rides and poor handling. Always choose tires according to the vehicle manual and check tire pressure before driving, measuring it when cold for accuracy. Regularly inspect tread wear—replace if depth is below 2mm. Safety is no trivial matter; don’t risk big losses for small gains. Ensure a safe journey.
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