Tyre designation

How do I tell what designation my tyres are?

Look at the sides of your tyres. You'll find a code of letters and numbers.

e.g. 205/55R16 88V

Each letter and number conveys important information, like whether a particular tyre will be compatible with your vehicle.

What do the letters and numbers mean?

Some tyre designations are prefixed with a letter

P

Passenger tyre

LT

Light truck tyre

T

Temporary tyre

 
 

 

 

Width of the tyre

The first number is a three-digit number which refers to the overall width of the tyre in millimetres.

e.g. 205/55R16 88V

Aspect ratio

The second number refers to the aspect ratio, which is the relationship between the tyre's height and its width. In this example, the sidewall's height is about 55% of the tyre's width.

The letter following the aspect ratio is usually an 'R' which stands for radial.

e.g. 205/55R16 88V

Wheel diameter

The next number indicates the diameter of the wheel rim (in inches) on which the tyre will fit.

e.g. 205/55R16 88V

Load index

The load index is an assigned number that corresponds with the load-carrying capacity of the tyre.

e.g. 205/55R16 88V

Speed rating

The speed rating is a letter which indicates the range of speeds at which a tyre is certified to carry a load. Each tyre is assigned a rating from A (lowest) to Z (highest).

e.g. 205/55R16 88V

Markings do not always appear exactly as they do in this example, as tyres can be certified under a variety of designations.