How often you should check your tyre pressures is one of the most common tyre questions Australian drivers ask — and the honest answer is: more often than most people actually do. Tyres lose air on their own, roughly 1–2 psi a month even with no puncture, and faster as the weather cools. Left unchecked, that slow drift below your placard pressure quietly costs you fuel, grip and tyre life. Here’s how often to check, when to do it, and the one wheel almost everyone forgets.

How often should you check tyre pressures?

At least once a month is the widely accepted baseline in Australia, and both the RACV and NRMA back a monthly-or-better routine. The NRMA suggests checking every week or two — or whenever you stop to refuel if you don’t drive much. On top of that regular check, top up your knowledge before any big drive.

Why do tyres lose pressure on their own?

Even a perfect, puncture-free tyre leaks. Air molecules slowly permeate through the rubber — typically 1–2 psi a month. Temperature adds to the drift: pressure moves by roughly 1 psi for every 5–6°C change, so a cold snap can drop you several psi in a morning and set off the warning light. Add the odd tiny bead or valve leak and it’s easy to be 4–6 psi down without noticing. That’s why seasonal swings and cold mornings are worth a re-check.

Should you check tyre pressures cold or hot?

Always aim for cold. A “cold” tyre means one that’s been parked for three or more hours, or driven less than about 2 km. Your placard figure is a cold pressure, so that’s the fair comparison. If you can only check after driving, the NRMA suggests adding about 2 psi to the placard number to allow for the heat — but the better habit is to check first thing, before the day’s driving. Never bleed a hot tyre down to the cold number, or it’ll be under-inflated once it cools. There’s more in our guide to cold vs hot tyre pressure and the placard vs sidewall question.

Does a TPMS mean you can stop checking?

No. A Tyre Pressure Monitoring System is a backstop, not a substitute for a gauge. Many systems only alert you once a tyre is already around 25% below its target — well into the danger zone — and some indirect systems can be fooled after a rotation or a manual top-up. Treat the light as a last line of defence, not a maintenance schedule. Our TPMS explainer covers how they work and when they lie.

What does a monthly check actually save you?

Keeping pressures right protects three things at once: fuel (under-inflation raises rolling resistance and burns more of it), tyre life (correct pressure wears the tread evenly, so you replace less often), and safety (proper inflation keeps braking and cornering predictable). Skipping the habit costs on all three — see what happens if you under-inflate and what happens if you over-inflate. It also feeds straight into your cost per kilometre.

Don’t forget the spare

A flat spare is no spare at all. Space-saver spares in particular are often specified at a high pressure (frequently around 60 psi) and lose air sitting in the boot for months. Check it every few months so it’s ready on the day you need it — the number is on the spare or in the handbook. See spare tyre pressure: the number everyone forgets.

Frequently asked questions

Is checking once a month really enough? It’s the minimum. Monthly catches the natural 1–2 psi drift before it matters. If you tow, carry loads, or notice a season change, check more often.

Can I check at the servo when the tyres are warm? You can, but add roughly 2 psi to the placard figure to allow for the heat, then verify cold when you can. A short drive to a nearby servo warms them less than a long run.

Do new cars still need manual checks if they have TPMS? Yes. TPMS warns late and can drift out of calibration. A monthly gauge check is still the standard of care.

How much pressure does a tyre lose per month? Around 1–2 psi from natural permeation, plus more if the weather cools or there’s a slow leak.

Bottom line

Check every tyre — including the spare — at least once a month and before every long trip, always cold, and don’t lean on the warning light to do the job for you. It takes five minutes and pays you back in fuel, tread life and safety.

Sources: RACV — tyre pressure guide; NRMA — car tyre pressure and maintenance. Figures are a guide; confirm your vehicle’s pressures on the placard.

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