How often should you check tyre pressure?

The short answer

every month

Once a month, and before a long drive. A tyre loses pressure on its own, roughly 1 to 2 PSI a month, with no puncture involved. Nothing about the way it looks separates a tyre that is right from one that is 15 per cent low.

Measure cold. After three kilometres of driving the air has warmed and reads several PSI high.

Where the right figures are

The vehicle placard is on the driver’s door pillar, sometimes inside the fuel flap or in the handbook. It usually gives two sets of figures: normal use and fully loaded.

The number moulded into the sidewall is not a recommendation. It is the maximum the casing will take.

What underinflation changes

The tyre flexes onto its shoulders, which wear on both edges while the centre stays new. Fuel use rises by a few per cent, wet braking distances grow, and sustained sidewall heat damages the casing.

Overinflation is not the safe side either: only the centre band touches the road, so grip and wear both suffer.

The steps

1. Read the placard on the door pillar

   Two sets of figures are common: unladen and fully loaded.

2. Measure cold

   In the morning, or after less than three kilometres, or the reading runs high.

3. Set all four tyres

   Forecourt airlines work; a pocket gauge costs little and saves the trip.

4. Look at the wear while you are there

   Uneven wear from one edge to the other points to alignment, not pressure.

Common questions