Below, we have an image of a typical tyre size – 205 55 16 - 91V

The numbers always break down in the following way:

205 The width of the tyre in mm. Typically, the higher the number, the more grip you get. But not always!

55 The profile of the tyre. The height of the sidewall expressed as a percentage of the width. So this one would be 112.75mm high. The lower the profile, the less the tyre distorts under sideways force, such as cornering, which is good for handling on performance cars. However, it also means there is less cushioning between the wheel rim and the road, so a low profile tyre is only really an upgrade if you want to prioritise handling over comfort.

17 This number is expressed in inches and indicates the diameter of the wheel on which the tyre is designed to fit.

91V On the sidewall of your tyre you will find a number followed by a letter.

The tyre load rating or load index (in our example: 91) is a code which corresponds to a maximum load (in kg) that can be carried by a single tyre.

The tyre speed rating (in our example: V) is a code which corresponds to the maximum speed at which a tyre can carry its maximum load.