What’s the difference between run flat tyres and normal tyres?

Collison run flat tyresWhilst modern vehicles save us the hassle and inconvenience of changing a wheel (a skill many of us still haven’t mastered) thanks to the presence a puncture repair kit instead of a spare wheel, utilising the sealant and compressor supplied can still make dealing with a flat tyre a real burden. However, it seems run flats provide the answer! But are run flat tyres really as effective as advertised? And how do they differ from your standard tyre? 

What exactly are run flat tyres?

Run flats are designed to keep your vehicle roadworthy even after one of the tyres has sustained a puncture. Run flat tyres provide a short term delay to the release of air from the tyre after a puncture happens, which means you can avoid those late night, roadside tyre changes and make your way home or to the nearest garage as safely as possible.

It’s important to remember that whilst a tyre blow out is inconvenient, it is also particularly dangerous, however, the self-supporting structure of the run flat can help minimise the hazards that go hand-in-hand with sudden tyre failure.

How does the structure of run flats differ?

As well as being equipped with the bead, steel belt, cap plies, body plies and inner liner that standard tyres are equipped with, run flat tyres come with a few special features for extra reinforcement. Run flats are constructed using a sidewall insert providing an additional 0.2 inches of rubber to the thickness of the tyre wall. Whilst this doesn’t seem like a lot, thanks to this addition, run flats are 5% stiffer than standard tyres.

Run flats also differ from standard tyres due to their cooling fins and complex compound. The cool fins actively reduce the temperature of the sidewall whilst complex compound is added to the reinforcing sidewall insert to decrease friction and further reduce the temperature of the tyres.

Thanks to these special additions run flat tyres can last another 50 miles – if driving at a speed of 30mph – giving you plenty of time to get home or to a local garage for help.

Why stick with or switch to standard tyres?

Whilst lots of modern cars come with run flat tyres as standard, many vehicle owners make the decision to change to standard tyres at their next replacement. Standard tyres tend to be cheaper and provide a smoother ride than run flats. Run flats must also be fully replaced and cannot be repaired like standard tyres for a temporary solution.

Before you do replace your run flat tyres with standard tyres however, you should seek professional advice to discover whether standard tyres are suitable for your particular make and model of vehicle.

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