Tyre Markings explained: How to read your tyre size?

Tyres have a lot of information moulded into the rubber on their sidewalls, but all the number and codes are baffling to most people, leaving them wondering, 'what does all the writing on the side of a tyre mean?'

Tyre sidewall markings are used to indicate the size and specifications of the tyre, providing important information about the size, brand and range they come from. Also, they show the tyre has passed the necessary safety standards imposed by UK or European law.

Due to the available space on the tyre sidewall, these markings are displayed in shorthand digits and abbreviations so they can be difficult to read, if you're not familiar with their meanings.

Type of Construction

This indicates how the tyre has been constructed. Most modern tyres are of radial construction, indicated by the letter 'R', whereas older tyres tend to be cross-ply.

Country of Manufacture

This indicates where the tyre has been made, in this is example, the tyre has been made in Great Britain.

Brand Name

The manufacturer of the tyre will be clearly printed on the sidewall of the tyre and will often be the largest marking.

Pattern Name

Tyre manufacturers design and sell a range of different tyre patterns unique to their brand. For example, in the example image, 'Dexel' would be the brand of tyre whilst 'Sport' would be the pattern name.

Tread Wear Indicators

Tread wear indicators are small blocks within the tyre tread that inform drivers when their tyres are approaching 1.6mm, the UK legal tyre tread minimum. Many tyre manufacturers denote where indicators are located with a mark on the sidewall; in our example it is the letters 'TWI', but Michelin tyres will display a small Michelin man and other manufacturers will use a triangle. Not all brands of tyre will carry this marking, so it is important that you check your tyre tread frequently to ensure that it does not fall below the legal minimum.

Tyre Size

The tyre size is indicated by three different numerical codes. It will be displayed like this: 205 / 55 / R16.

205 is the width of the tyre displayed in millimetres

55 stands for the aspect ratio. This is the tyre sidewall height displayed as a percentage of the width.

R indicates type of construction

16 is the nominal diameter of the wheel rim that the tyre has been designed to fit. This figure is displayed in inches.

Load Index

This figure refers to the maximum load that a tyre can carry. Look for the load index on the sidewall of your tyres and from the below load index table, you will be able to find the maximum load that you can carry in kilograms.

Speed Rating

The speed rating of your tyre is similar to the load index, it is a key which relates to a corresponding table and tells you the maximum speed you can travel on your tyre, when inflated to the correct pressure and carrying maximum load.

When buying new tyres, make sure that the speed rating matches the speed capabilities of your vehicle. Dexel Tyre & Auto Centre recommend that you fit tyres with the speed rating that the vehicle manufacturer specified for the vehicle. It is important to note, however, that you can choose to fit tyres with a higher speed rating if you wish, but you must not fit tyres with a lower speed rating.

If you require further guidance on reading your tyre sidewall markings, contact your local Dexel Tyre & Auto Centre where one of our tyre specialists will be able to offer more advice.