How to read your tyre sidewall markings
Your tyre’s sidewall contains all the information about your tyre that you’ll need. Here’s a little guide to what all those numbers and letters mean:
A. Tyre width
The width of your tyre, in millimetres, measured from sidewall to sidewall.
B. Aspect ratio
This is the ratio of the tyre’s cross-section to its width, expressed as a percentage. An aspect ratio of 65, for example, indicates that the tyre’s height is 65% of its width.
C. Wheel diameter
The diameter (height) of the wheel in inches.
D. Load index
Your tyre’s load index relates to its maximum carrying capacity (in kg). You’ll find the load rating of your tyre on the sidewall, just to the right of the diameter.
For example, a tyre with a load index of 91 can carry 615kg of weight.
Load ratings and speed ratings should be looked at together when you buy a new tyre. Also remember to check your manufacturer’s recommendations.
E. Speed rating
The speed rating is the maximum speed for a tyre when it is correctly inflated and being used under load. The speed rating is the letter at the end of the sidewall, after the load index number. A tyre with a speed rating of V, for example, has a maximum speed of 240 km/h.
When buying new tyres, make sure you match their speed rating with the speed capabilities of your vehicle.
A “P” or no letter at all indicates a passenger car tyre.
The letter “R” stands for radial. Almost every new tyre built today is a radial tyre.
ECE approval mark and number
This tells you that the tyre conforms to the standards of the United Nations Economic Commission for Europe (U.N.E.C.E.) in relation to pneumatic tyres.
Tyre pressure information
This is the maximum inflation pressure for your tyre. Consult your vehicle’s manual for more information about recommended tyre pressure because it can have an impact on your car’s handling, turning, braking and fuel efficiency.
Tread wear indicators
The letters “TWI” show the location of the tyre’s tread wear indicators. You should check these indicators regularly to ensure there’s enough tread on your tyres. In most EU countries the minimum tread depth 1.6mm.
This four-digit code tells you the week and year that your tyre was manufactured.