How do you tell if a tyre is flat or just needs air?

By Julia Freeman

When it comes to car tyres, it is not always obvious as to whether they just need air or are actually ‘flat’. Indeed, a flat tyre is most commonly the result of slow air leakage, making it more difficult to notice. Sometimes, however, it is more obvious - for example if you are driving and it suddenly blows out. If this happens, you will feel a significant vibration and hear a loud thump followed by a flapping noise.

If you are unsure whether you have a flat/puncture or your tyre just needs air, the easiest way to check is to go to a garage, add air to the tyres (as per your owner's manual) and then wait for a while and see what happens. If it stays inflated then it was simply out of air. If not, and you can feel or hear that air is escaping, then it is punctured and will likely need replacing.

Common causes of a flat tyre

Puncture by a sharp object

The number one cause of a flat tyre is a puncture due to a sharp object.

Damage to the valve stem

Another common cause of flats. A damaged valve stem can result in air leaking from the tyre, making it eventually go flat. Dirt can also clog-up the stems, resulting in air loss.

Rubbed/ripped tyre

A worn or ripped tyre can lead rapidly to a flat. If any of your tyres are deeply scuffed or worn then you should seek advice and look at replacement.

Tyre bead leaks

The bead is the element at the edge of the tyre which connects with the wheel rim. If air leaks from here, it can result in the tyre becoming flat over time.


Hitting a kerb when parking can cause the tyre to slip slightly away from the rim. This can result in a slow loss of air over time, and eventually, a flat tyre.

Over-inflated tyres

Over-inflation can often result in a blowout.

Road hazards

Potholes, unexpected debris and uneven roads can all cause damage to your wheels, axles, and tyres – including causing blowouts.
If you know or suspect that you have a flat tyre, you should avoid driving until it has been checked over by an expert. If it is a flat and can’t be repaired, it will need to be replaced.

Book with Protyre

At Protyre, we stock a range of premium tyres from brands including Pirelli, Bridgestone, and Goodyear, mid-range tyres from manufacturers including Avon, Toyo, Yokohama, and economy tyres from brands such as Nankang and GT Radial. All of our garages are staffed by experienced mechanics and qualified fitters.
To identify some potential tyre options, why not use our tyre search function by simply entering your registration number? Or you could search using your tyre width, profile, and rim size. If you would like to get your tyres checked, you can book a free tyre check with one of our tyre professionals at your local Protyre garage; simply enter your postcode in our online search to find your nearest garage.

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About the author

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By Julia Freeman
Julia is Head of Retail Marketing for Protyre and loves engaging with customers and the business as a whole to make sure Protyre is more than just a local garage.
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