How do I find the correct tyre pressure for my car?

The correct pressures are specified by the vehicle manufacturer and can be found: on the tyre pressure placard inside the driver's door frame or door pillar, in the vehicle handbook, or sometimes on a label inside the fuel filler flap. The pressures are specified in PSI (pounds per square inch) or bar. Note that some vehicles specify different pressures for front and rear tyres, and some have different recommendations for fully loaded vehicles.

How often should I check tyre pressure?

At least once a month and before every long journey. Tyres naturally lose a small amount of pressure over time — typically around 1 PSI per month. Temperature changes also affect pressure: cold weather reduces pressure by approximately 1 PSI per 10°F (5.5°C) drop in temperature. Regular checking keeps you aware of any tyre developing a slow puncture.

What happens if I drive on over-inflated tyres?

Over-inflated tyres wear in the centre of the tread (a diagnostic wear pattern), have a reduced contact patch with the road, provide a harder ride, and are more vulnerable to impact damage such as kerb strikes or potholes. They do not fail an MOT directly, but the resulting wear pattern may eventually cause failure or require early replacement.

What happens if I drive on under-inflated tyres?

Under-inflated tyres wear on both shoulders (edge wear), generate excessive heat due to increased sidewall flex, reduce fuel economy, compromise handling and braking, and are significantly more likely to suffer a blowout. Under-inflation is one of the most common causes of tyre failure. It also wastes fuel — a tyre 20% under-inflated increases fuel consumption by around 2%.

Should tyre pressure be checked when tyres are hot or cold?

Always check when cold — before driving or after no more than a couple of miles of low-speed driving. Driving builds up heat in the tyre which increases pressure. If you check a hot tyre, the reading will be higher than the actual cold pressure, and you may deflate a tyre that is actually at the correct pressure.

Does tyre pressure affect MOT results?

Incorrect tyre pressure does not directly cause an MOT failure in itself. However, significant under-inflation can affect brake testing results and may influence the tester's assessment of the tyre's condition. Over-inflation causing visible centre wear can lead to an advisory. Checking and correcting pressure before your test is straightforward good preparation.

MotR

Tyre Pressure · Safety Guide

Tyre Pressure Guide

Incorrect tyre pressure is one of the most common — and easily avoided — causes of tyre wear, blowouts and increased fuel costs. Here is how to check, what pressures to use, and why it matters.

DVSA DataDVLA RecordsFree · No SignupUpdated 2026

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Updated 13 June 2026·5 min read·Reviewed by Ste Robinson, MotR

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Quick Answer

Find correct tyre pressure on the placard inside the driver's door frame or in the handbook. Check when tyres are cold (before driving). Check at least monthly. Front and rear may differ. Fully loaded vehicles often need higher pressures. Under-inflation is more dangerous than over-inflation — it causes heat buildup, shoulder wear, and increases blowout risk.

Effects of Wrong Tyre Pressure

Effect	Under-inflated	Over-inflated
Wear pattern	Both shoulders (edge wear)	Centre strip (centre wear)
Safety risk	Higher — blowout risk, heat buildup	Moderate — reduced grip, impact damage risk
Fuel economy	Worse — more rolling resistance	Slightly better but difference is marginal
Ride quality	Softer, more wallowing	Harsher, more impact felt
Braking	Extended wet stopping distances	Slightly reduced contact patch
Tyre lifespan	Significantly reduced	Reduced (but less than under-inflation)

How to Check Tyre Pressure

Check when cold

Tyre pressure builds up with driving heat. Check before a journey or after less than 2 miles of driving to get an accurate cold reading.

Find correct pressure

Door frame placard or handbook. Usually stated in PSI or bar. Note if different for front/rear and for loaded/unloaded.

Use a reliable gauge

Petrol station gauges can be inaccurate. A digital gauge from a motor factor (~£10) gives consistent readings.

Check all four plus spare

Check each tyre individually. Include the spare — a flat spare is useless in an emergency.

Record and compare

If a tyre regularly loses pressure faster than others, it may have a slow puncture. Monitor over a few weeks and have it checked.

Tyre Pressure FAQs

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Ste Robinson

Founder, MotR · Last reviewed 13 June 2026

Ste Robinson is the founder of MotR, helping UK drivers check MOT history, tax status, vehicle records and ownership information using official DVLA and DVSA data.

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