Why automakers favour run flat tyres today


August 16, 2020 By Mike
Last updated on August 16, 2020

If you’ve never owned a vehicle with run flat tyres, you may be wondering what on earth they are. In simple terms the major difference between the two is that a run flat is design to keep your vehicle roadworthy even after one of the tyres has had a puncture, whereas a standard tyre would force you to stop your car immediately. Run flat tyres are becoming more and more popular among car manufacturers, and in this article we’re going to explore why.

How does the structure of a run flat differ to a standard tyre?

Not only featuring the bead, steel belt, cap piles, body piles and inner lining that your standard tyre comes with, a run flat tyres also boasts a few additional features for extra reinforcement. They’re constructed using a sidewall insert which offers an additional 0.2 inches of rubber to the overall thickness of the tyre wall. And although 0.2 inches doesn’t seem like a lot, this actually makes your run flat tyres around 5% stiffer than standard tyres.

They also have cool fins which actively reduce the temperature of the sidewall, and a complex compound which reinforces the sidewall to decrease friction and reduce the temperature of the tyres.

Because of these innovative additions, your run flat tyres can last another 50 miles, if you’re driving at 30mph, which gives you ample time to get home or to a local garage to get the help you need to change your punctured tyre.

Why do manufacturers opt for run flats?

Car manufacturers such as BMW definitely favour run flats over standard tyres. In fact, according to Monty Roberts from BMW Product and Technology communications has said that fun flat tyres are standard in most of their models, with the exception of some of the M models.

They’re mainly used by car manufacturers such as BMW, Mini and Mercedes because they eliminate the need for a spare tyre, jack and tools in the vehicle, which gives the car better balance, handling and fuel efficiency.

What are the main benefits to having run flat tyres?

The main advantage of run flat tyres is that you can carry on driving if you get a puncture. You do have to be careful however, with how much further you drive on the tyre and how fast you go – the distance limit should be enough to allow you to get somewhere to change it, whether that’s at home or a tyre fitters.

Because of their strong sidewalls they’re also less prone to blowouts, which are potentially dangerous especially when you’re travelling at high speeds.

Another advantage, and one of the reasons that some car manufacturers use them is that you don’t need to carry a spare wheel, creating ample space in the boot and even under-floor or deeper storage.