What are run flat tyres? Our guide

What is a run flat tyre?

When it comes to picking a tyre type for your car, there are various options to choose from. One specific type you might find when doing research are run flat tyres.

However, you may not know exactly what run flat tyres are or how they work. Our handy guide takes a closer look at everything you need to know about run flat tyres and some of the frequently asked questions around them.

If you drive often, there’s a high chance you’ve experienced a puncture at some point on your travels. And although getting a puncture can be very frustrating, it’s also very common – in fact, it’s one of the most common reasons for vehicle breakdowns.

Punctures happen due to a number of reasons – you may have driven over a nail, hit a rock or even driven over one of the UK’s many potholes!

Data released in January 2024 by Round Our Way, revealed that there were around 1.2 million potholes in the UK, which means the risk of drivers damaging or puncturing a tyre while out on the roads is a very real threat.

With that in mind, you can never be too prepared when you are out and about on the roads. One way to prepare yourself in advance is by getting yourself some run flat tyres. But what exactly are they?

When standard tyres are punctured, due to the sudden loss of pressure, the tyre will no longer be fit for purpose and must be changed as soon as possible. However, run flat tyres, thanks to their specially reinforced sidewalls, give drivers the ability to continue their journey for a limited time when they have no pressure in the tyre.

It's recommended that drivers travel for a maximum of 50 miles and not exceed 50mph when driving on a run flat tyre.

How do run flat tyres work?

Run flats are tyres that have a reinforced sidewall construction, which isn't found on standard tyres. This super-tough construction allows the run-flat tyre to support the car even if it has experienced a puncture.

Therefore, a punctured run-flat tyre will allow the car to be safely driven for a limited time, as opposed to standard tyres, which would need replaced almost instantly after a puncture.

How to identify a run flat tyre

There are four ways of checking and identifying a run flat tyre. Remember, if you need help you can always contact us and one of our dedicated Product Geniuses will be happy to assist you with identifying if your tyres are run flat or not.

1. Step 1

   

   Firstly, check the marking on your tyres. The majority of run flat tyres will have specific markings on the sidewall, such as Run Flat, RSC (Run System Component), SSR (Self-Supporting Run flat), RFT (Run Flat Technology), ROF (Run On Flat), or similar abbreviations. These markings may differ depending on the tyre manufacturer.

2. Step 2

   

   Secondly, keep an eye out for any manufacturer branding for run flat tyres. For example, Bridgestone labels their range of run flat tyres DriveGuard. Continental run flat tyres will usually always have 'SSR' and 'RSC' labelling, as seen in the photo above.

3. Step 3

   

   Next, look for the International Organization for Standardization (ISO) symbol that indicates run flat tyres. It is made up of a circle containing the letters RSC (Run-Flat System Component) and is located on the sidewall of the tyre.

4. Step 4

   

   Finally, if you're still unsure if your car has run flat tyres, check the owner's manual or vehicle specifications provided by the manufacturer. This should be able to tell you whether or not run flat tyres are installed as original equipment on your vehicle.

What are the benefits of run flat tyres?

There are three main benefits of run flat tyres. Firstly, the strengthened sidewall of a run flat tyre will help a driver keep control of their car in the event of a puncture. In comparison, if a standard tyre experiences a puncture, the sudden loss of air pressure could cause the driver to lose control of the vehicle.

If you do experience a puncture on a run flat tyre, you won't need to change your tyre immediately like with a standard tyre. This means you should be able to drive to somewhere suitable to change your tyre, instead of having to do it at the side of the road, which can be dangerous on motorways or other busy roads.

Having run flat tyres also means you won't need to carry a spare wheel. Without the need of a heavy spare wheel, you'll have more space in your boot and, with less overall weight, your fuel efficiency will benefit.

Can I mix and match run flats with standard tyres?

It’s important that you don’t mix run flat and standard tyres. Run flats are only fitted to new cars which have a tyre pressure monitor system (TPMS), which detects when there is a puncture.

This will show up as a warning on the vehicle’s dashboard. For this warning to be accurate, the car would need to be fitted with run flat tyres on all four wheels. Similarly, if you wanted to run tyres with standard tread, you would need to do so on all four tyres.

Run flats often come as ‘Original Equipment’ – the tyres the car is fitted with when it leaves the factory. In turn, this may mean the car has been designed so that it doesn't need a spare tyre cavity in the boot.

If you replace a run flat with a non-run flat and then have another puncture, with no spare tyre in your boot, you could be left stranded. It’s best to keep this in mind when deciding whether to replace your run flat or look to buy a spare tyre.

If you've purchased a car second hand and you’ve found that there’s no spare wheel in the boot, it's best to check if the tyres are run flats.

Your questions answered

What are the downsides to using run flat tyres?

Due to the weight of run flat tyres, they can impact the car's handling and reduce fuel efficiency.

Do I have run flat tyres?

It's worth noting that not every car will come equipped with run flat tyres as standard. The best way to check if your car has run flat tyres is to check whether you have a spare wheel under your boot bed or if it’s a tyre repair kit.

As run flat tyres were invented to save drivers carrying a spare wheel, it's most likely that if you have a spare tyre in your boot, then your car is fitted with standard tyres.

Can you repair a run flat tyre?

It's highly recommended that you do not repair a run flat tyre, and instead, replace it as soon as possible. Due to the reinforced design and structure of a run flat, it is extremely difficult to tell whether there's secondary damage and if the internal structure has been affected.

How far can you drive on run flat tyres with a puncture?

Run flat tyres allow drivers to continue their journey even when they have no pressure in the tyre, but that doesn't mean it's a permanent solution. Drivers are recommended to drive for a maximum of 50 miles and at a maximum speed of 50 mph while using a run flat tyre.

Overusing a run flat tyre could cause significant damage to the wheel itself, so it's better to get it replaced sooner rather than later.

Are run flats tyres more expensive the normal tyres

Run flat tyres are usually more expensive than standard tyres, with some costing up to 50 per cent more. However, many drivers believe paying extra is worth it because it provides additional safety in the case of a puncture.