When should tyre pressures be checked?

Checking your car’s tyre pressures at least once a month is better for your safety and your wallet

By Gavin Braithwaite-Smith Sept 1, 2022

When did you last check your car’s tyre pressures? If you can’t remember, it might be time to grab a pressure gauge, because as your car’s only point of contact with the road, it’s vitally important to get it right.

Most tyre manufacturers recommend checking the pressure of each tyre at least once a month. Michelin, Dunlop and Falken all say once a month, while Continental suggests checking the pressures every two to four weeks.

According to Dunlop, a tyre will lose about 1psi or 0.069 bar per month. An underinflated tyre will wear out more quickly, with Michelin advising that a 7psi or 0.5 bar difference from the manufacturer’s recommendation could reduce the life of a tyre by a rather significant 8,000km (5,000 miles).

Pressure per inch (psi) is the imperial system used for tyre pressures, while bar is metric. Both systems are used in the UK.

A tyre will lose pressure due to a number of reasons, including a slow puncture, a faulty valve or valve cap, an old alloy wheel or even a fall in temperature during the winter months. Checking the pressure at least once a month will ensure you identify a potential problem before it becomes a big issue.

There are many reasons why tyres should be inflated to the recommended pressures, including braking performance, grip, and the impact on ride comfort. Then there’s the cost of getting it wrong, with Michelin saying a tyre inflated by 14psi (1 bar) will increase fuel consumption by one tank of fuel per year. Given the current cost of petrol and diesel, that’s a significant chunk out of the household budget.

How to check tyre pressure

You need to find the correct tyre pressure for your car. This is likely to be listed on a sticker, either inside the driver’s door or on the back of the fuel filler cap, but you’ll also find it in the vehicle handbook. If in doubt, consult your local car dealer or use one of many tyre pressure checker tools you’ll find online.

Don’t assume that the pressures for the front tyres will be the same for the back tyres. There will also be different pressures in relation to various loadings, which could be important if you’ve filled the boot and roof box with luggage for your summer holiday.

To check the pressure, you’ll need a pressure gauge or tyre pump. These are relatively inexpensive to buy, but you’ll also find a pressure gauge and pump at most petrol stations. An all-in-one tyre inflator could cost as little as £10, while the use of the pump at a petrol station could cost a pound.

Our advice would be to buy an inflator with +/– buttons to enable you to select the desired pressure. The inflator will switch off when the pressure reaches the required limit.

With a suitable pressure gauge and pump to hand, follow these steps:

  1. Remove the dust cap from the tyre valve and keep it safe. Many people lose these, which puts the tyres at risk of losing pressure
  2. Place the pressure gauge onto the valve stem to get an accurate reading
  3. Check to see if the tyre is over- or under-inflated
  4. Use the pump or electric compressor to inflate the tyre to the recommended pressure
  5. If the tyre is over-inflated, use a small screwdriver to release the air
  6. Refit the dust cap
  7. Check the tyre pressures within a month

Don’t forget to check the spare tyre (if fitted) because you don’t know when you might need it.

If you’re not convinced that checking your tyre pressures is an important part of running a car, it’s worth noting that if your tyres are over- or under-inflated enough to be considered unroadworthy, you could be stopped by the police. In the worst-case scenario, you could receive a £2,500 fine and three penalty points per tyre.