About tyre sizes

Tyre codes

All tyres have a tyre code that is used to identify it and this is found on the sidewall of your tyres.

This code serves two main purposes, the first is to identify the size and specification and the second is to confirm the tyre has been tested to approved safety standards.

Your vehicle handbook will confirm your vehicles tyre speed and load ratings as well as any additional requirements.

Get to grips with tyre sizing

The tyre coding might look confusing at first but once it’s broken down it’s easy to understand.

The tyre size is made up of several parts, the width of the tyre in millimetres, the profile (percentage of the width), the diameter of the inner rim and the load and speed ratings.

Please see the image below with corresponding legend - which describes the tyre code in detail:

• A - 215mm - this is the nominal width of the tyre
• B - 55% - described as the aspect ratio, this mark represents the height of the tyre sidewall as a percentage of the nominal section width
• C - ZR - is a tyre of radial construction - which is suitable for cars with a with a speed capability over 240 KPH (150mph).
• D - 16 inches - this is the diameter of the tyre's inner rim in inches
• E - 97 - this is the load capacity of the tyre
• F - W - this is a speed symbol indicating the maximum speed for this tyre at full load - in this case up to 168mph