Tyre pressure is one of the easiest safety checks to carry out yourself. Traficom recommends checking pressures at least once a month and always following the vehicle manufacturer’s instructions for the load being carried.
Why does the pressure change?
Tyre pressure drops as the air cools, and rises as the tyre warms up while driving. Colder autumn weather can therefore change the reading even without tyre damage. The load, in turn, affects the inflation pressure recommended by the vehicle manufacturer. Check the values for a loaded car before setting off.
Incorrect pressure changes how the car behaves
Incorrect tyre pressure impairs handling and can shorten the tyre’s service life. Pressure that is too low also increases rolling resistance and energy consumption. Looking at a tyre is not enough to judge its pressure; it needs to be measured.
Where can you find the correct value?
Use the vehicle manufacturer’s recommendation. It can usually be found in the owner’s manual, on a door pillar or near the fuel filler flap. Note the different values for normal and full loads, and for the front and rear tyres. Choose the instructions for your tyre size. The maximum pressure marked on the tyre’s sidewall is not the car’s recommended pressure.
How to check the pressures
- Measure cold tyres before driving or after they have cooled down. Follow the vehicle’s instructions on cooling time.
- Check the unit on the gauge. For example, 2.5 bar means 250 kPa; this is an example of unit conversion, not a general recommended inflation pressure.
- Remove the valve cap and connect the gauge securely to the valve. Use the device according to its instructions.
- Adjust the pressure to the vehicle’s specified value and measure again. Replace the valve cap.
- Repeat for all tyres. Also check any spare wheel against its own specified value.
After driving, the reading may be higher than the cold tyre pressure. Do not reduce a warm tyre’s pressure to the value intended for a cold tyre; check it again once the tyre has cooled down.
If one tyre repeatedly loses pressure
Note the tyre’s position and the measured pressure. Ask a tyre specialist to investigate a leak if the same tyre constantly needs more air. Simply inflating it will not repair damage to the tyre or valve. If a tyre is clearly deflated or damaged, find out what is safe to do before continuing to drive.
A tyre pressure monitoring system does not measure pressure directly in every car: some detect changes from tyre rotation. The absence of a warning light therefore does not replace regular measurement. If a warning comes on while driving, stop in a safe place and check the tyres according to the vehicle’s instructions. Only save the pressures or reset the system, if required, after checking and correcting them, as described in the owner’s manual.
Traficom: Summer and winter tyres for cars.
Nokian Tyres: Tyre pressure and What is TPMS?. Tesla: Tyre pressures supports the distinction between measurements on cold and warm tyres; always check model-specific values and procedures in your own vehicle’s instructions.
Information checked on 8 October 2026. The checklist is a practical compilation by the editorial team.
