A car tyre’s speed rating represents the maximum speed at which it is designed to perform at. The speed rating on tyres is represented by a single letter than you can find on the markings on your tyres sidewall and in the vehicle handbook.
When it comes to buying new tyres it’s important your new replacements have the correct speed rating for your car, both for safety reasons and for insurance purposes. If you want a professional opinion on the suitability of your car tyres, you can book in at any Stoneacre garage in the UK for a free car tyre check.
UK Tyre Speed Index – the different tyre speed ratings
Speed ratings on tyres are fairly simple to understand once you have a comparative value in miles per hour (mph). You can easily find the speed rating on your current tyres by looking at the markings on the tyre sidewall. It will look something like this – P205/55 R 16 91S.
The tyre speed rating is indicated by the last alphabetic letter, which in the above example is ‘S’. Take a look at the tyre speed rating chart below for a comparison between the speed rating on tyres and the max speed in mph.
What is a tyre speed rating?
Speed ratings for tyres are determined by industry standards and are set by testing at simulated speeds. For a tyre to receive a rating it must demonstrate that it can perform as desired at a particular speed. This means the integrity of the tyre remains intact, performance is maintained for cornering and traction, and the safety of the tyre isn’t compromised.
Manufacturers like Bridgestone point out that tyre testing is done in a controlled environment and that performance will also be affected by other factors like tyre inflation, tyre wear, weather and road conditions, and the mechanical condition of the car. With this in mind tyre speed ratings may at times be less then the stated rating of the tyre. For tips on keeping tyres working in optimal condition, read our 9 tips for tyre maintenance.
Why is speed rating important?
Car tyres are the only point of contact with the road so they must be able to cope with the demand of the car when accelerating, cornering and braking. At faster speeds more heat is created from the friction between the tyre and road surface, so tyres must be able to cope with these conditions.
Tyres that are driven at speeds in excess of their tyre rating are less able to cope with the demand on performance. They are likely to wear much faster and the chance of a blowout is increased too. Not only will faster speeds cause strain on your car tyres, but accelerated tyre wear will likely have knock on affects for other parts of your car like the suspension and wheel bearings.
For obvious safety reasons, using tyres with a lower speed rating than what’s recommended by the manufacturer may invalidate your car insurance policy. Insurance companies expect your car to be in ‘road worthy condition’ and will take exception to using tyres with a low speed rating. These exceptions also apply to other dimensions of your tyre too. Take a look at our guide to understanding tyre sizes so you can check other dimensions of your car tyres.
Are tyres with a higher speed rating better?
Tyres with a higher speed rating are not necessarily better in terms of quality, but they do offer better performance. Most passenger vehicles in the UK will require a speed rating of at least S or T, and more performance based cars that are capable of speeds in excess of 120mph will need tyres with a speed rating of U and above.
Depending on what you buy, tyres with a higher speed rating will generally offer better handling, cornering, acceleration and braking performance, which is why some drivers may choose tyres with a higher speed rating than what’s recommended for their car. There’s nothing wrong with using a V, W or Y rated tyre for your car even if your manufacturer recommends a S or a T.
Buy tyres online with a certain speed rating
At Stoneacre we sell a wide range tyres online from the leading brands with local fitting available across England and Wales. Finding tyres for your car that have the correct tyre rating is easy with us, simply enter your car registration to view a selection of tyres recommended for the make and model of your car. Or you can manually enter the desired size of your tyre if you want a tyre with a particular speed rating. This makes it easier to find the right set of tyres from leading manufacturers like Bridgestone, Pirelli, Dunlop and Goodyear.