- Tyres-Tips/Guides
No more feeling stressed when your tyre springs a puncture in the dark, no more wondering who you can call for help, no more looking in the boot only to find your spare tyre is flat too. Getting stranded with a flat tyre is a thing of the past with run-flat tyres.
What is the purpose of a run-flat tyre?
A Run-flat tyre allows you to continue driving for a while longer after it has been punctured, with the purpose of getting you to a safe place rather than being stuck and worried. Due to their unique construction, they also minimise the potentiality of rapid, explosive tyre pressure loss – commonly known as a blowout.
What’s the difference between run-flat and conventional tyres?
With regular tyres, your car is supported by the air in your tyres. When that air is allowed to escape the tyre collapses, putting strain on the rest of the vehicle’s components.
Run-flat tyres are much heavier because they are built with reinforced sidewalls and tough rubber inserts. This allows the tyre to continue supporting the weight of your car temporarily after a puncture.
Overall, the benefits of run-flat tyres comes at a premium – they are not repairable, cost more to replace, and are not as readily available as conventional tyres.
What types of run-flat tyres are there?
Different manufacturers use different technologies in their run-flat tyres. There are two primary types of run-flat tyre systems:
- Self-supporting – in general, they feature stiffer, thicker, reinforced sidewall construction consisting of layers of rubber and heat-resistant cord. This prevents sidewalls from folding or creasing under pressure.
- Support ring – also known as auxiliary-supported, it consists of a hard rubber support ring attached to the wheel.
How does a run-flat tyre work?
Despite the fact that they’re built differently, run-flat tyres still need to be pumped with air and work like conventional tyres to support and spread the weight of the vehicle. When punctured, they’ll lose their air, but due to their structural support, you will hardly notice any tyre deflation. This is why vehicles fitted with run-flat tyres as original equipment (OE) include a tyre pressure monitoring system (TPMS) that detects air pressure loss and alerts the driver on the centre console.
How to use run-flat tyres
You should always seek guidance from your vehicle manufacturer or tyre supplier on the correct use of your run-flats.
- Once punctured – reduce driving speed. Check the tyre manufacturer’s specification for the distance you should be able to drive for and up to what speed. For example, Bridgestone says their run-flats can continue for up to 80km at a maximum speed of 80km/h. But this does depend on driving speed and conditions, as well the car’s load, so rather stay well below the maximum.
- Pumping up – and keeping the correct air pressure is necessary and must be done as frequently as a conventional tyre.
- Changing to conventional tyres – is possible but check with your car manufacturer or dealer for written confirmation. Some manufacturers do not recommend it as it could influence the car’s handling. If you do decide to switch, make sure you equip your car to carry a spare tyre.
- Changing from conventional tyres – should only be done on vehicles fitted with a tyre pressure monitoring system.
- Mixing tyres and brands– should be avoided as much as possible as run-flat and conventional tyres offer different characteristics. Tyre brands also have their own dynamics and handle differently.
- Repairing run-flats – is generally not recommended for the long-term as the tyre’s strength may have been compromised, and the extent of the damage is difficult to ascertain. You can however have small punctures temporarily repaired with the same method as conventional tyres.
- Regular maintenance – is not much different as the rate of tread wear and life span is similar to conventional tyres.
- Mounting and de-mounting – must be done carefully and by a professional.
Whichever tyres your car is fitted with, safety is the most important consideration. Keep your tyres maintained with periodic wheel alignment and wheel balancing, and remember that Supa Quick also offers you a free vehicle safety check.
Disclaimer: This information is for educational, or entertainment purposes only. It must not be construed as advice, legal, financial, or otherwise. We do not make any warranties about the completeness, reliability, and accuracy of this information. The views expressed in this article are the views of the author and not necessarily the views of Supa Quick.
