How Do Run-flat Tyres Work?

Most run-flat tyres use reinforced sidewalls that are strong enough to support the vehicle temporarily when tyre pressure is very low. This is different from a conventional tyre, whose sidewall is not designed to carry the vehicle safely when deflated.

How Far Can You Drive on a Run-flat?

The permitted distance and speed depend on the tyre manufacturer, tyre design, vehicle and degree of damage. Do not rely on a single universal mileage or speed figure. If a run-flat loses pressure, follow the vehicle and tyre manufacturer’s instructions and reduce speed.

A tyre-pressure warning should be treated seriously. Stop when it is safe, inspect the tyre if possible, and arrange assistance if there is visible damage or the vehicle does not feel safe to drive.

Advantages of Run-flat Tyres

• They can provide limited mobility after pressure loss.
• They may remove the need for a conventional spare wheel.
• They can reduce the need to stop immediately in an unsafe roadside location.
• Vehicles designed for run-flats normally use a tyre-pressure monitoring system to alert the driver to pressure loss.

Things to Consider

• Run-flat tyres are often more expensive than equivalent conventional tyres.
• The reinforced sidewall can affect ride comfort, depending on the tyre and vehicle.
• Not every vehicle is suitable for changing from run-flat to conventional tyres without considering wheel, suspension, TPMS and manufacturer requirements.
• A tyre that has been driven with little or no pressure may have internal damage that cannot be judged from the outside.

Can a Run-flat Tyre Be Repaired?

Repair suitability depends on the tyre manufacturer’s guidance, the location and type of damage, and whether the tyre has been driven while deflated. Because hidden structural damage can occur, any suspected run-flat puncture should be removed from the wheel and assessed professionally rather than repaired automatically.

See our puncture repair guide and tyre-pressure warning-light guide for related advice.