How to check tyre pressure: gauges, cold readings, placard

To check tyre pressure, find your car’s recommended pressure on the sticker inside the driver’s door or the fuel flap, then measure each tyre with a gauge while the tyres are cold, before you have driven more than a couple of kilometres. Unscrew the valve cap, press the gauge firmly onto the valve, read the figure, and add or let out air until it matches the sticker. Do all four tyres and the spare, refit the caps, and repeat once a month and before any long trip. That is the whole job. The rest of this guide explains where people go wrong: reading the wrong number, checking hot tyres, and trusting an uncalibrated gauge.

How to check tyre pressure, step by step

1. Find the right pressure. Look for the placard on the driver’s door pillar or inside the fuel filler flap, or check the owner’s manual. It usually gives separate front and rear figures, and sometimes a higher pair for a fully loaded car.
2. Check with the tyres cold. Michelin recommends checking when the car has been driven less than about 2 km, or has not been used for a couple of hours. At home, first thing in the morning is ideal. At a fuel station, choose the one nearest your home.
3. Remove the valve cap and keep it somewhere safe.
4. Press the gauge or the air line’s nozzle squarely onto the valve. A short hiss as it seats is normal and does not change the pressure meaningfully.
5. Read the pressure and compare it with the placard.
6. Adjust. Add air if it is low; press the valve core or the gauge’s release button to let air out if it is high. Measure again.
7. Refit the cap. Michelin notes that a missing valve cap lets the valve leak and that a good seal depends on it.
8. Repeat for every tyre, including the spare. For a motorcycle or scooter, see our guide to bike tyre pressure.

Where to find the right tyre pressure for your car

Do not use the number moulded on the tyre. The MAX PRESS marking on the sidewall is the most the tyre can take, not the pressure your car needs, and Michelin warns specifically against using it. The right figure comes from the car maker, which sets it for that model and tyre size.

Your car’s figure is printed:

• on a sticker on the driver’s door pillar or on the back of the fuel filler flap,
• in the owner’s manual, usually in the tyres or specifications section.

If the placard gives a “laden” or “full load” pressure, use it when the car is carrying a full set of passengers and luggage, then return to the normal figures afterwards. Our tyre pressure lookup lists makers’ recommended figures for Indian cars by variant, and the cars pages show the tyre sizes that go with them.

Cold vs hot tyre pressure

Tyres warm up as you drive, and warm air pushes the pressure up. A reading taken after a long run will look high even if the tyre was correct when cold. The mistake to avoid is letting air out of a warm tyre to match the placard: once it cools, it will be under-inflated.

If you have to check after driving, Michelin’s rule of thumb is to add 0.3 bar (about 4.35 psi) to the recommended pressure, set the tyre to that, and then check again when the tyres are cold. Never deflate a warm tyre.

Choosing and using a tyre pressure gauge

Fuel station air lines are convenient, but Michelin cautions that their gauges are not always calibrated, so readings can be off. Use them to add air, but check the result with your own gauge if you can.

A personal gauge, digital or dial, kept in the glovebox, gives consistent readings. Michelin advises using the same gauge every time, so that differences between instruments do not mislead you.

A portable compressor that plugs into the car’s power socket lets you check and adjust at home. Most have a built-in gauge.

Psi, bar and kPa

Placards and gauges may show psi, bar or kPa. One bar is 100 kPa and about 14.5 psi, so 2.2 bar is about 32 psi. Our psi to bar converter handles any figure.

How often to check tyre pressure

Once a month, and before every long trip. Tyres lose air even when nothing is wrong: Michelin puts the normal loss at about 0.1 bar (1.45 psi) a month, and faster through a porous valve, a corroded rim, or a slow puncture. A tyre that has lost much more than the others since the last check deserves a professional look.

Even if your car has a tyre pressure monitor. The warning light is designed to come on only when a tyre has lost a large share of its air. Under the international rule for these systems, the warning must appear once a tyre is about 20% below its normal pressure. Michelin’s point is that by then the tyre is already under-inflated and wearing faster. Our guide to TPMS explains how the systems work.

What wrong tyre pressure does

Under-inflated tyres wear out faster and less evenly, make the car less precise to steer, and run hotter, which at high speed can end in tyre failure. Michelin says a tyre run 20% under its correct pressure can lose about 20% of its life.

Wrong pressure either way reduces grip and lengthens braking distances, and under-inflation raises fuel consumption.

The spare and nitrogen-filled tyres

Check the spare too. It is easy to forget until the day you need it. Michelin suggests checking it at least once or twice a year, and at every monthly check is better still.

Tyres filled with nitrogen are checked in exactly the same way, with the same gauge and the same placard pressures. Nitrogen slows pressure loss a little; it does not remove the need to check. Our guide to nitrogen vs air explains the difference.