How to read your tyre sidewall markings

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:

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.

Higher load indexes and different speed ratings

It may be possible to fit tyres with higher load indexes and different speed ratings to those indicated in your vehicle’s manufacturer documentation.

However, always check first in your vehicle’s manufacturer documentation if these tyres may be fitted on your vehicle and if using these tyres is permitted under your local laws and regulations. You should also comply with all applicable requirements of your local laws and regulations and not exceed the specifications of these tyres as well as those indicated in your vehicle’s manufacturer documentation in terms of speed and load.  Your dealer may help you verifying this before purchasing or fitting tyres.

Is it possible to fit tyres with a higher speed rating than my manufacturer recommends?

Yes, this may be possible. However, always check first in your vehicle’s manufacturer documentation if these tyres may be fitted on your vehicle.

Is it possible to fit tyres with a higher load index than my manufacturer recommends?

Yes, this may be possible. However, always check first in your vehicle’s manufacturer documentation if these tyres may be fitted on your vehicle.

Is it possible to fit tyres with a higher speed rating and a higher load index than my manufacturer recommends?

Yes, this may be possible. However, always check first in your vehicle’s manufacturer documentation if these tyres may be fitted on your vehicle.

Is it possible to fit tyres with a lower speed rating than my manufacturer recommends?

Yes, you can use all-season or winter (M+S) tyres that have a lower speed rating so long as: a) a sticker that shows the maximum speed limit is in the driver’s field of vision and b) you don’t drive the vehicle faster than the maximum speed limit. However, always check first in your vehicle’s manufacturer documentation if these tyres may be fitted on your vehicle.

Is it possible to fit tyres with a higher load index and a lower speed rating than my manufacturer recommends?

Yes, you can fit tyres that have a higher load index and a lower speed rating.

You can use all-season or winter (M+S) tyres that have a lower speed rating so long as: a) a sticker that shows the maximum speed limit is in the driver’s field of vision and b) you don’t drive the vehicle faster than the maximum speed limit.

However, always check first in your vehicle’s manufacturer documentation if these tyres may be fitted on your vehicle.

 

Warning

Check your vehicle owner's manual to determine the load limits. Overloading your vehicle places stress on your tyres and other critical vehicle components. It can cause poor handling, increased fuel consumption and may cause tyre failure. It can also result in severe cracking, component separation or "blowout." 

Tyre type

A “P” or no letter at all indicates a passenger car tyre.

Construction

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.

Production date

This four-digit code tells you the week and year that your tyre was manufactured.