If you’ve bought a car and are worried that there’s neither a spare tyre nor a foam filler kit in the boot, you may have thought that it was missing, presumably used by a previous owner, but it could be that your car is fitted with run flat tyres and so doesn’t need a spare or a repair kit.
There can be much confusion regarding run flat tyres, so here at Bodymek, we explain exactly what run flat tyres are and give you the facts you need to determine whether your vehicle has run flat tyres or not.
What are run flat tyres?
The clue is in the name; run-flat tyres allow you to continue driving even when they are flat.
That doesn’t mean you can drive normally, though, once the air has escaped, you can only drive on a ‘flat’ run-flat tyre for a restricted number of miles and at a lower speed (ideally not above 50 mph). The idea is that you can come to a safe, controlled stop.
How do they work?
Unlike conventional tyres, which require air to stay hard, run flat tyres have a reinforced sidewall, meaning they stay rigid without any air pressure.
The reinforced outer shell of run flat tyres keeps the rubber in place without air, supporting the car as you continue your journey. However, the sidewall isn’t designed to be permanent and is only recommended for around 50 miles of addition driving after the tyre has deflated.
How to tell if my vehicle has run flat tyres
Run flat tyres are easily identifiable by symbols on the sidewall of your tyre. Although there is no standard code to indicate run flat capabilities, most tyre manufacturers have their own run flat markings. Below is a list of the best-selling premium run flat tyre brands and the symbols they use to identify run flats.
-Bridgestone – ROF, RFT, RSC
-Pirelli – RSC
-Michelin – ZP
-Goodyear – ROF, EMT
-Dunlop – DSST, ROF
-Continental – SSR
How will I know if I have a puncture with run flat tyres?
You will be able to tell if you have a puncture or low tyre pressure from the alarm within your vehicle alerting you to the wheel pressure sensors. You may also feel an increase in the force required to turn the steering wheel as well as the car pulling slightly over to the tyres damaged side.
You may also hear an increased noise whilst driving and when driving at high speeds (above 90mph), you may feel vibrations or the sensation of the wheel banging.
Are run flat tyres repairable?
Although damage is unlikely on run flat tyres, it is sometimes unavoidable. However, we would never recommend repairing a damaged run flat. Once the sidewall of these tyres has been compromised, the strength, durability and safety of the tyres will be significantly reduced.
One of the main reasons it is advised against is if the deflated or damaged tyre has been driven on, there is no way for a fitter or garage to know how long or how fast the tyre has been driven on and therefore, won’t know how best to fix it. Because of this, most fitters will not even offer to repair your run flat and instead will recommend replacing it.
As best practice, we would recommend replacing the tyre as soon as you notice a puncture or damage, or your car’s system has alerted you to a drop in tyre pressure.
If you’re not sure how to tell if the tyres on your car are run flats or not, or to get other useful tyre advice and support, pop down to our Northamptonshire garage and speak to one of our expert tyre professionals who will be happy to assist.
