Understanding how to read tyre sizing can be quite confusing, but it is essential to ensure you buy the right tyres for your vehicle. Tyre sizing information can be found on the sidewall of your tyre and is usually a combination of letters and numbers. In this article, we will break down the different components of tyre sizing to help you understand what each one means.
The first part of a tyre size is usually a letter, which indicates the type of vehicle the tyre is designed for. The most common letters are:
- P: Passenger vehicle
- LT: Light truck
- T: Temporary spare
- ST: Special trailer
Following the letter, there are three numbers that represent the tyre’s width in millimetres. For example, if the tyre size is P215/65R15, the width of the tyre is 215 millimetres.
After the three-digit number, there is usually a forward slash, which is followed by two numbers. These two numbers represent the aspect ratio of the tyre, which is the height of the tyre’s sidewall as a percentage of the tyre’s width. In the example above, the aspect ratio is 65, which means that the height of the tyre’s sidewall is 65% of its width.
The next letter in the tyre size is “R,” which stands for “radial.” Almost all tyres on the market today are radial, so you’ll see “R” in almost every tyre size. However, there are other types of tyres, such as “D” (diagonal) and “B” (belted), which are less common.
The next number in the tyre size is the diameter of the rim in inches. In the example above, the tyre size is 15 inches in diameter.
Finally, there may be additional letters and numbers at the end of the tyre size that provide additional information about the tyre. For example, “M+S” indicates that the tyre is suitable for mud and snow, while “XL” indicates that the tyre has an extra load capacity.
It’s worth noting that sometimes tyre sizes are written slightly differently. For example, you might see “215/65R15 95H” instead of “P215/65R15.” In this case, the “95H” at the end of the tyre size refers to the load index and speed rating of the tyre.
The load index is a number that represents the maximum weight that the tyre can carry, and the speed rating is a letter that indicates the maximum speed that the tyre can safely travel. The load index and speed rating are important because they ensure that the tyre is suitable for the weight of your vehicle and the speeds you’ll be driving.
In conclusion, understanding how to read tyre sizing can be confusing, but it’s essential to ensure that you buy the right tyres for your vehicle. By breaking down the different components of tyre sizing, you’ll be able to decipher what each part means and make an informed decision when it comes to buying new tyres.