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Guide · Pressure and TPMS

Over-inflated tyres: what risks do you run?

In brief

With over-inflated tyres the contact patch shrinks: you get less grip, especially in the wet, potentially longer braking distances, a less comfortable ride and wear concentrated in the centre of the tread. The tyre also becomes more vulnerable to impacts with potholes and kerbs. The fix is to bring the pressure back, with the tyres cold, to the value given by the manufacturer on the label or in the manual.

  • Less rubber on the road = less grip, especially in the wet
  • Wear concentrated in the centre of the tread
  • Greater risk of damage from potholes and kerbs
  • Only correct it with the tyres cold
On this page
  1. What happens if your tyres are over-inflated?
  2. Is an over-inflated tyre more easily damaged?
  3. How can you tell if your tyres are over-inflated?
  4. Why do tyres end up over-inflated?
  5. How do you correct pressure that is too high?
  6. Impact damage after driving on hard tyres?
  7. Frequently asked questions

What happens if your tyres are over-inflated?

If your tyres are over-inflated, the tread bulges out and touches the road mainly with its central part: the contact area shrinks.

  • Grip: less rubber on the road means less grip, especially on wet or uneven surfaces.
  • Braking and cornering: the car may feel less precise and slide sooner.
  • Comfort: the tyre absorbs less of the road's unevenness, so the ride becomes harsh and noisy.
  • Wear: the centre of the tread wears faster than the shoulders.

Is an over-inflated tyre more easily damaged?

Yes: an over-inflated tyre is stiffer and absorbs impacts less well, so hitting a pothole or kerb hard can damage it more easily.

Typical impact damage includes cuts and bulges on the sidewall, a sign that the internal plies have broken: read a bulge in the tyre and, if the impact also affected the wheel, damaged wheel rim.

How can you tell if your tyres are over-inflated?

The reliable way to tell is to measure the pressure with a gauge when the tyres are cold and compare it with the manufacturer's value. Some signs may still make you suspect too much pressure.

  • A harsher, noisier ride than usual, "bouncing" over bumps.
  • Tread worn mainly in the centre (see uneven tyre wear).
  • A feeling of less grip in the wet.

Note: a high reading straight after a long journey is normal, because the tyre is hot. Check again when cold.

Why do tyres end up over-inflated?

It happens mainly for three reasons: the wrong value is used, the pressure is measured with inaccurate instruments, or people forget to return to the normal pressure after a fully loaded trip.

  1. The "max press" value on the sidewall: this is the maximum pressure the tyre can withstand, not the operating pressure.
  2. The "full load" value left in place even when the car is back to travelling unloaded.
  3. Inflating a cold tyre in a warm place, or an inaccurate gauge.
  4. Mixing up units between bar and psi on the air line.

You can find the right value as explained in what your tyre pressure should be.

How do you correct pressure that is too high?

You correct it by letting a little air out of the tyre when it is cold, pressing the central valve pin in short bursts and checking with the gauge until you reach the manufacturer's value.

  1. Make sure the tyres are cold.
  2. Remove the cap and briefly press the valve pin.
  3. Measure, then repeat until you reach the correct value.
  4. Put the cap back and check all the wheels.

If the tyre is hot, do not let air out: the higher pressure while driving is expected by the manufacturer.

Impact damage after driving on hard tyres?

If after a pothole you notice a cut, a bulge or a tyre losing air, do not underestimate it and do not keep driving for long. Read can you drive on a flat tyre?

In Milan and its province, SOS Tyre comes out 24/7, in 30 minutes on average, to wherever you have stopped, and assesses on the spot whether the tyre can be repaired. Call +39 377 326 0999.

Frequently asked questions

Does inflating the tyres more save fuel?

The correct pressure reduces rolling resistance compared with under-inflated tyres, but going above the manufacturer's value to save fuel is not advisable: you lose grip, braking can get worse and the tread wears unevenly. The right value is the one on the label.

Is a few tenths of a bar too much a problem?

A small difference from the manufacturer's value is not an emergency, but it is better to correct it. Some manufacturers give a higher value only for full loads or high speeds: use it in those conditions and go back to the standard value when they no longer apply.

Does TPMS also warn of pressure that is too high?

It depends on the system. TPMS is designed mainly to warn of pressure drops; some direct systems show the value for each wheel and can also highlight excess pressure, others cannot. Do not rely on the warning light to spot over-inflated tyres: measure with a gauge.

Can over-inflated tyres burst?

If you stick to the manufacturer's value, the risk of a blowout from over-pressure is very remote, because the tyre is designed for a much higher maximum pressure. The real risk of over-inflated tyres is loss of grip and greater vulnerability to impacts with potholes and kerbs.

Guide by the SOS Tyre editorial team · Updated on . This information is general in nature: for your vehicle, always refer to the owner’s manual.

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