What Do Tyre Speed Ratings Mean? | Dowleys, Oxfordshire

WHAT IS A TYRE SPEED RATING?

The speed rating of a tyre indicates the maximum speed that it can be driven at safely. Displayed on the sidewall of the tyre, you'll find its speed rating, diameter of the wheel, depth of the sidewall and width of the tyre.

A tyre's speed rating is indicated by a single letter at the end after the load rating.

WHY IS A TYRE SPEED RATING IMPORTANT?

Your wheels turn faster when you're travelling at higher speeds, which generates more heat from the increased friction with the road. As such, the speed rating is in place to ensure that your tyres can cope with this extra heat.

Travelling with a tyre that has a speed rating below its usage creates a risk that it will fail at high speeds - this is potentially very dangerous and could cause you to have an accident.

CHOOSING YOUR SPEED RATING

The tyre rating on most modern cars doesn't actually reflect the speed that the vehicle is capable of. For example, most family cars have a speed rating of H (130mph) or V (149mph), whereas smaller city cars tend to have T-rated (118mpg) tyres.

This is predominantly a safety precaution to ensure that the performance of the tyre exceeds the performance capabilities of the car. A higher speed rating means that the tyres are able to cope with the rigours of acceleration, braking and high-speed cornering.

When it comes to choosing the speed rating of your tyre, you should never fit anything lower than the manufacturer's original fit - doing this can invalidate your insurance. If you want to, there's no problem with picking a tyre that has a higher speed rating.

If you're not sure what tyre speed rating you should choose, you can call us on 01933 842 345 or send an email to service@dowleys.co.uk and we'll be happy to help you find the correct tyre for your car.

The table below displays a tyre's maximum speed and its rating:

Speed Rating	Maximum Speed (mph)
N	87
P	93
Q	99
R	106
S	112
T	118
U	124
H	130
V	149
Z	150+
W	168
Y	186

The system is based around the European use of kilometres, which is why speed ratings in mph are at such unusual increments.

Speed ratings are achieved by engineers running the tyre at 6.2mph steps, in 10 minute increments, until the required speed has been met.

When it comes to replacing your tyres, we want to make the process as simple as possible. We stock tyres from all the major brands to accommodate a range of budgets. For more information, please contact us.