The problem with tyre punctures is that oftentimes, they result in a slow leak. Leaks over a long period of time will result in an underinflated tyre.
The danger with underinflated tyres is that when being driven at high speeds they get hot, and it’s this heat that causes permanent sidewall damage and increases the chance of a tyre blowout.
What are run flat tyres?
Run flat tyres, or RFTs, are speciality tyres designed to be operated (for short distances at least) while they contain little to no air pressure.
Modern run flat tyres are designed with a much stiffer sidewall than standard tyres that can support the weight of the vehicle when the tyre is flat.
Many RFTs specify a maximum speed of up to 80k/ph for a maximum distance of 80 kilometres, but your individual tyre may have slightly different speed and maximum distance requirements. Generally the heavier your vehicle is, the shorter the distance you can safely drive without causing permanent tyre damage.
Make no mistake, run flat tyres can get punctures and damage, just the same as other tyres, but they might get you back to a tyre store before the situation leaves you stranded somewhere.
Types of run flat tyres
The concept of a run flat tyre isn’t new, although original designs for run flat tyres actually had nothing to do with the tyre, rather the wheel was the special component. Run-flat wheels contained an inner band that supported the tyre. This method had many benefits such as smoothness over bumps and low noise, but was very expensive and made fitting tyres very difficult and time consuming.
Modern run-flat tyres look more or less the same as regular tyres, except the tyre sidewalls are much thicker and stiffer in order to support a vehicle’s weight. This style of runflat can sometimes give a harsher ride with more noise transferred into the vehicle from the road, but vehicle manufacturers tend to fit vehicles equipped with RFTs extra sound deadening and specifically fine-tune the suspension to mitigate this.
Run Flat Tyre Fitting
Due to the much stiffer sidewalls and heavier duty shoulders, run flat tyres can often be more difficult to mount.
Run flat tyres also require a specially designed wheel that grips the tyre bead and prevents the tyre rolling off the rim when being driven on whilst ‘flat’.
Because of the stiffer sidewalls and shoulders, it’s very hard to visually tell whether a tyre is low on air like you can with regular tyres, this is why nearly every vehicle you see with RFTs also have some kind of tyre pressure monitoring system, or TPMS for short.
As such, to avoid damaging expensive genuine wheels and expensive run flat tyres, you should trust your tyres to the professionals at Donnellans.
Can Run Flat Tyres be Repaired?
Generally, yes. Because all vehicles that come factory fitted with run flat tyres also have TPMS, it’s very common to find, and repair a damaged tyre early on, before too much air has leaked from the tyre.
If you’re in a situation where you’ve needed to take full advantage of a run flat tyre’s capabilities, driving for an extended period of time, the sidewall may have sacrificed itself in order to ensure you make it safely to your destination.
This is why, regardless of how damaged a tyre looks, we recommend taking the tyre off the wheel and performing a full inspection before advising repairs or replacement run flat tyres.
Victoria’s Run Flat Tyre Specialist
Donnellan's are your local run flat tyre specialist and we carry a huge range in stock at all times, including OE sizes suitable for popular BMW, Audi, Porsche, Lexus and Volkswagen models.
Our staff are trained and experienced with fitting run flat tyres to both OEM and aftermarket wheels. We can also move your factory TPMS system over to a new set of aftermarket wheels if required.
Use the contact form on this page, or choose your local Donnellans workshop and call us to book in your vehicle today.