How to read tyre codes
Have you ever noticed the letters and numbers written on the side of your car’s tyres?
For your information, these letters and numbers are not randomly placed by the tyre manufacturers. Each of them has a specific meaning that can help you choose the right tyres for your vehicle.
What should you look for when selecting tires?
Besides the brand and the tyre model itself, you need to choose the correct tyre size. Tyres don’t come in Small, Medium, or Large sizes like clothing; instead, you should look for a sequence of numbers and letters that might be written like this:
175/65 R14 82H
It may seem confusing to the uninitiated, but deciphering the code above is not rocket science.
Firstly, the number “175” represents the width of your tyre in millimeters. Therefore, the tyre above has a width of 175 mm.
After the slash, the number you see is the aspect ratio, which tells you how tall your tyre profile is. It’s not in millimeters but as a percentage after dividing a tyre’s height off the rim by its width.
Hence, “65” here means the tyre’s height is 65% of its width.
Next, the letter “R” refers to the construction of the tyre, which is Radial. This is the most common construction for passenger vehicle tyres.
The number after R indicates the size of the rim diameter in inches. This means a tyre with the 195/55 R15 dimension would fit a 15-inch rim.
The next number indicates the load index, the maximum load a single tyre can carry at full inflation. Each number corresponds to a specific load capacity listed in an index. For instance: “85” means the tyre can carry a load of up to 515 kg.
The letter after the load index refers to the tyre’s designed speed capability or in other words, it’s the fastest speed a tyre can handle before its performance is affected. The letter H means thys tyre can reach a speed of 210 km/h.
You can also find out when a tyre was manufactured by looking for a four-digit code usually located near the Department of Transport (DOT) marking.
The first two numbers indicate the week, and the last two numbers are the production year. Therefore, the code “0523” indicates that the tire was manufactured in the 5th week of the year 2023.
