Wrong tyre pressure is the most common, cheapest-to-fix fault we see - and the easiest to get right at home. It costs you fuel, eats your tread, dulls the steering and lengthens stopping distances. This guide covers checking it properly, finding the correct figures, and what the dashboard light is actually telling you.
Where To Find The Correct Figures
Your car's official pressures are printed on a sticker inside the driver door frame or fuel flap - never rely on a sidewall figure, which is the tyre's maximum, not your car's recommendation. Figures usually appear in both bar and psi, and most cars show separate values for normal and fully loaded driving.
How To Check Properly
Check when the tyres are cold - before a journey or at least three hours after one, since driving heats and inflates the air inside. Press the gauge firmly onto the valve, read the number, and adjust if it differs from the sticker. If the pressure sits low, fill it; if it is over, let air out in short bursts. Twist the valve caps back on by hand - they keep out dirt and are your first defence against slow leaks.
How Cold Weather Changes Things
Pressure drops roughly 0.1 bar for every ten-degree fall in temperature - an overnight frost can quietly knock the whole car down by a couple of psi. That is normal physics, not a leak, but it matters: winter mornings are exactly when you want full-contact rubber. Add a monthly winter top-up to your routine, and revisit the fully-loaded figures before a heavy trip.
Load, Towing And The Rear Axle
The door sticker lists a higher rear pressure for loaded motoring - and for towing, both axles move up. If you regularly pull a caravan or trailer, set the car's pressures for the loaded state and keep the caravan tyres on their own correct figures too. Under-pressure plus a heavy trailer is how tyres overheat on motorways.
What The TPMS Light Means
The tyre pressure monitoring light usually glows amber for a slow pressure loss and red, or flashing, for a serious drop. If the amber light appears, check and top up every tyre, then drive a short distance - most systems reset automatically, some need a manual reset from a menu or button. A fast deflation, a thumping ride or a visible bulge means stop driving and call us; if the light returns regularly you have a slow puncture worth finding. Though we will happily scan and set all four correctly, TPMS is the dashboard reminder, not the repair.
Pressure And Tread Work Together
Even pressure means even wear - the single best defence for your tyre budget. Run the pressures right and the same set lasts thousands of miles longer; run them wrong and the pattern tells on you, as our wear pattern guide explains. Not confident with a gauge? Drop in any day - pressure checks are free, take minutes and come with a full tread and sidewall look-over.
Frequently Asked
How often should I check my tyre pressure?
Monthly is the sensible minimum, before long journeys, and after a week or more of the car standing still. Cold tyres at home always beat a warm roadside reading.
Can I trust petrol station air machines?
Good for a top-up, but their gauges are often inaccurate - treat them as a quick fix and verify against the door sticker. We set yours accurately and free.
What happens if I drive on a flat?
If the marker on a run-flat fails, or any tyre goes fully flat, stop as soon as it is safe - driving a few hundred metres can destroy the sidewall beyond repair.