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Burst or Exploding Tyres - The What, Whys, and Hows

  • Tyres-Safety-Tips/Guides-FAQs

Unfortunately, tyres can and do burst unexpectedly. Most drivers fail to notice the signs until it's too late. Exploding tyres can be extremely dangerous to yourself and other road users.

What is a tyre burst?

A tyre burst, also known as a tyre blowout, occurs when the structural integrity of the tyre is compromised. When this happens, the tyre rapidly loses pressurised air. The pressure of escaping air tears through the tyre’s surface which results in it exploding.

In short, a tyre burst or explosion is a rapid loss of inflation pressure from an air-filled(pneumatic) tyre, often accompanied by a loud bang as it explodes.

What are the possible causes of a tyre bursting?

1. Heat - the underlying cause

Heat is the underlying cause of a tyre exploding. The buildup of temperature inside a tyre causes the pressurised air there to warm up and start expanding. When the tyre gets too hot, the rubber begins to degrade and after a length of time ruptures. Higher temperatures during the summer months put more pressure on the air inside a tyre.

Excessive heat is caused due to a variety of reasons:

2. Incorrect tyre inflation

Temperature is directly proportional to pressure. Under-inflation is one of the most common reasons for a tyre bursting. An under-inflated tyre suffers from excessive flexing which increases its contact with the road surface leading to accumulated friction resulting in overheating of the tyre.

Over inflation can also cause a tyre to burst for a variety of reasons.

  • Driving in high temperature conditions can cause over expansion of the tyre.
  • If the tyre is faulty, damaged, or old.
  • Damaged or faulty wheel rim.

The heat build-up from an incorrectly-inflated tyre can be much higher than if you were simply driving in the heat of a sweltering summer day.

Also read: The Importance of Correct Tyre Pressure

3. High-speed driving

Two factors that cause blowouts influenced by speed:

  • Distance – Driving fast for long distances causes increased tyre pressure, and along with friction on hot road surfaces, tyres are more susceptible to bursting. This is why blowouts are more common in summer.

Speed rating – All tyres are manufactured in such a way that can withstand specific speeds up to a certain point. Driving faster than your tyre’s speed limit rating is one of the major reasons for tyre bursts as the tyre’s structure will not be able to handle the higher friction levels beyond its limit and give in. To find your tyres’ speed rating, look at the symbols on the sidewall. The speed rating is generally the last item in the sequence and ends in “S”.

Image source: Bridgestone

4. Faulty tyres

Old or secondhand tyres are less dependable due to wear and tear.  Diminished tread, cuts, cracks, bulges are just some dangers that can lead to accidents and tyre blowouts.

Tyres have a limited lifespan and last on average between 25,000 to 50,000 kilometres for drivers with normal driving styles.

Also read: How Long Do Tyres Last?

5. Collision with an object

Objects on the road, like potholes, sharp rocks, fallen bricks, or hitting a pavement – anything that could cut or tear the tyre’s at a particular point where the pressurised air could not be contained can result in a blowout.

6. Weight of the vehicle

Just as semi-trucks have weight restrictions, so does your car. If overloaded, undue stress is placed on the vehicle’s tyres. This becomes a potential risk for a burst tyre if there is uneven tread wear and causes the weakest tyre to blowout. Rotating your tyres can help prevent uneven wear.


Tyre bursts can be fatal, especially if you're driving on the highway. Fortunately, today’s tyres are more technologically sound to handle the stresses of driving. However, it’s advisable to have your tyres checked annually after three years of having them fitted and change them as soon as you notice the tread is less than 1mm*.

Visit a convenient Supa Quick Fitment Centrefor a free Vehicle Safety Check.

*Under South African law, the legal limit for a tyre tread grove shouldn't be below 1mm across the entire tread surface of the tyre's circumference.

Read next:

Can Tyre Blowouts Be Prevented
What to Do If Your Tyre Bursts

Also read:

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.


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