What is a Tyre Speed Rating?

Speed ratings are a vital part of choosing the correct tyres for your car, but many owners don't know about it. Getting it wrong could prove to be very expensive – and can even make your car less safe – so read on for our full guide to tyre speed ratings.

A stack of tyres

Why are tyre speed ratings important?

The tyre speed rating is the maximum speed that a tyre can be safely driven at. Maintaining speeds higher than this legally-approved limit puts pressure on the tyre that it was not designed to handle, and that can lead to the tyre failing. Not only could this cause an accident that endangers you and other road users, but it can also invalidate your insurance.

How do I choose the right speed rating?

A car should never be fitted with tyres that have a lower speed rating than those it was originally fitted with. If you don’t know the correct tyre ratings for your car, a quick look in the vehicle handbook should tell you all you need to know. If you’re looking at the existing tyres, you’ll find the rating on the sidewall – it’s the letter at the end of the numbers (for example,195/75 16Q). It’s now also fairly common to be able to find the right speed rating online by inputting the car registration.

What are the different tyre speed ratings?

Because you should be fitting tyres with a speed rating in line with the vehicle’s top speed, you’ll probably be fitting nothing lower than an N (87 mph) – most likely much higher. Tyre speed ratings increase by about 6 mph with each letter so P is 93 mph and Q, 99 mph. The top speed rating is 186 mph, if you’re lucky enough to have a car that fast.

Strangely, the top-rated tyre is not the letter Z. In fact, it’s not quite as straightforward as progressing through the alphabet:

  • N – 87 mph
  • P – 93 mph
  • Q – 99 mph
  • R – 106 mph
  • S – 112 mph
  • T – 118 mph
  • U – 124 mph
  • H – 130 mph
  • V – 149 mph
  • Z – 150+ mph
  • W – 168 mph
  • Y – 186 mph

What about the cost?

Tyres with a lower speed rating may be cheaper, but it’s not a saving you can choose to make. On top of the increased possibility of accidents, having tyres with the wrong speed rating could get you into trouble with the police or invalidate your insurance policy.

On the flip side, while it’s perfectly fine to put tyres with a higher speed rating on your car, it may cost you more money for no added benefit.

Now you know what speed ratings are, why they’re important and how to find the right one for your car, make sure to factor it in the next time you’re buying tyres. Not doing so could cost you more than you bargained for.

Need more advice on your car tyres? Read up on how to check your tyre tread to make sure you’re always legal and our ten step guide on how to change a tyre in case you’re caught out with a flat.

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