What are run flat tyres and how do they work?

Q: What are run flat tyres?

Run flat tyres are a type of tyre that allow a vehicle to continue driving safely even if the tyre has been punctured or suffered a sudden loss of air pressure. Once a tyre has lost pressure, a run flat will be able to allow the motorist to continue driving for around 50 miles. Giving them enough time to get home or find somewhere safe to stop. In this instance, it is recommended that the vehicle does not exceed 50mph.

Q: How do run flat tyres work?

There are different types of run flat tyre technology, but most run flat tyres work by using a special construction to keep the tyre’s shape in the event of pressure loss. This normally is a reinforced sidewall. These are designed to support the weight of the vehicle and allow the tyre to keep it’s shape. The other type of run flat tyre technology is one that makes use of a special sealing compound that can temporarily seal punctures in the tread. Again, allowing the driver to continue driving if the tyre is punctured.

Q: Are run flat tyres worth it?

It depends on the individual driving needs and preferences. Run flat tyres can provide peace of mind and convenience - as the need to stop and change a tyre in the event of a puncture is removed. However, they can be more expensive, and some drivers find them to be less comfortable and noisier.

Run flat tyres are designed to keep you moving after a puncture, removing the need for an immediate roadside tyre change.

What are run flat tyres?

Run flat tyres are a type of tyre that allow you to continue driving after a puncture or sudden loss of air pressure.

Most run flat tyres let you drive for up to 50 miles at a reduced speed of up to 50mph, giving you enough time to reach home or a safe location.

They are commonly fitted as standard on vehicles from manufacturers such as BMW, MINI, and Mercedes-Benz.

How do run flat tyres work?

There are two main types of run flat tyre technology:

Reinforced sidewall run flat tyres
This is the most common type. These tyres use thicker, reinforced sidewalls that can support the weight of the vehicle even when air pressure is lost. This helps the tyre retain its shape and maintain control.

Self-sealing run flat technology
Some run flat systems use a special sealing compound inside the tyre. This can temporarily seal small punctures in the tread area, reducing air loss and allowing you to continue driving.

Both designs are intended to give drivers enough time to reach a safe location.

How far can you drive on a run flat tyre?

In most cases, you can drive:

Up to 50 miles
At a maximum speed of 50mph

It is important not to exceed these limits, as driving further or faster can cause internal damage to the tyre.

Are run flat tyres safer than normal tyres?

Run flat tyres offer several safety advantages:

Reduced risk of blowouts
Greater control after a puncture
No need for a roadside tyre change
Safer option for motorway driving

However, there are some trade-offs:

A firmer ride, which may reduce comfort
Increased road noise

Are run flat tyres worth it?

Whether run flat tyres are worth it depends on your driving needs and preferences.

Advantages

Continue driving after a puncture
No spare wheel required
Improved safety in certain situations

Disadvantages

Higher purchase cost
Firmer ride comfort
Limited repair options

Can you change from run flat tyres to normal tyres?

Yes, it is possible to switch from run flat tyres to standard tyres, but there are some important considerations.

All tyres should be replaced as a matching set
Your Tyre Pressure Monitoring System (TPMS) may need adjustment
You may need to inform your insurer

It’s also worth noting that many vehicles fitted with run flat tyres do not include a spare wheel.

Can you mix run flat tyres with normal tyres?

Although UK law does not specifically ban mixing run flat and standard tyres, it is not recommended.

Run flat tyres have stiffer sidewalls and behave differently to standard tyres. Mixing them can:

Affect handling
Reduce grip
Make the vehicle feel unstable

For safety and performance, tyres should always be fitted in matching pairs or as a full set.

Can run flat tyres be repaired or plugged?

In most cases, run flat tyres should not be repaired.

Because they are designed to support the vehicle after losing pressure, internal damage may occur when driven while deflated.

Plugging run flat tyres is generally not recommended
Many manufacturers advise against repairs entirely
Some allow limited repairs under strict conditions

If a run flat tyre is punctured, it should always be inspected by a qualified tyre professional before any decision is made.