Tyre Speed Rating

If you are not very confident in automotive matters and you are about to change your car tyres, then we have something for you –  a portion of useful information about tyre speed rating - what it is and why it is important and how you should read tyre speed rating and ratings charts. Once you know that, you are very likely to avoid the risks associated with wrongly selected tyres, so don’t stop reading here!

Tyre speed rating example

What is the tyre speed rating?

The tyre speed ratingis the maximum permitted speed at which the car can move with the specified tyre type under the maximum load defined by the tyre load index. These two parameters are dependent on each other and they must be always taken into account when fitting tyres to a car.
The speed ratingis marked on the side of the tyre with letters and numbers. Any planned change of tyres should correspond with the speed index compliant with the recommendations of the car manufacturer, as stated in the car type-approval. When specifying tyre parameters, the manufacturer takes into account the car's power, mass and other features that affect driving safety. 

Seasonal tyres and speed rating

For summer tyres, tyres with a speed rating lower than that specified by the manufacturer should never be used.
It is different in the case of  winter tyres. The speed rating for snow tyres and rules for its selection are defined by EU legislation (Directive 92/23/EEC). According to these regulations, winter tyres may have their speed rating lower than recommended by the manufacturer, but not lower than index Q (Q = 160 km/h).

If the car is provided with tyres of a lower speed rating, then the appropriate designation should be visible to the driver. Finally, although it is permitted, you should thoroughly consider the use of tyres with a lower speed index. They may wear faster and your car may respond differently than before. To ensure a safe and comfortable drive, the speed rating of your tyres should not be lower than the type-approved index by more than one degree.

Changing the speed rating of your tyres.

Each designation marked on the tyre sidewall provides valuable guidelines that should be followed, when selecting new tyres for your car. The proper selection of tyres ensures safe and comfortable driving. The most important values that need to be taken into consideration when choosing tyres include size, load rating, speed rating, date and place of manufacture.

What may be the consequences of using tyres with wrong tyre speed rating?

●      Dangerous driving. Improperly selected tyres may cause a different response of the car to the driver's steering action.
●      The tyre may blow causing a serious accident.
●      In the case of a collision or traffic incident, the insurer may refuse to pay insurance based on a wrong selection of tyre speed rating.
●      Loss of guarantee for the purchased product. Installing the wrong type of tyres on your car makes their guarantee void.
●      A police officer in the course of a routine control may issue a fine for having the wrong tyres fitted.

Pros and cons of using higher tyre indices

It is possible to mount tyres with higher load and speed indices than those provided by the manufacturer. Is it worth changing the tyres on those that have higher indexes?

Tyre speed rating chart: