November 1, 2014

How To Check Car Tyre Pressures

Checking Your Tyre Pressure

Checking your car’s tyre pressures regularly (at least once a month) is one of the most useful and profitable things you can do for your car.

Under-inflated tyres will increase your car’s fuel consumption, wear out faster and reduce your car’s stability. Up to 2 pounds of air escapes naturally each month from a car tyre, even without a puncture.

Slow punctures can cause a tyre’s pressure to fall without you noticing it – only by regular checks will you catch it before you damage the tyre or have a blow out.

How Do I Check My Tyre Pressures?

Every car has different recommended tyre pressures and they are often different for the front and rear wheels. Check your car’s user manual to find out what pressures are right for your car. If you don’t have the manual, try this car tyre pressure search tool.

Your car’s tyres should be cool when you check their pressure. Ideally, this means that you won’t have driven the car for around an hour. If you do not have your own pump to use at home, try using a supermarket garage air pump after you have done your shopping – that way, you will only have driven a few hundred yards from where you were parked and your tyres should have cooled down.

Here’s how to do it:

  1. Pull up to the pump so that the air hose will reach all four of your wheels without you needing to move the car.
  2. If the pump is coin operated and only gives you a limited time, take of the dust caps on all 4 wheels before you put your money/token in – this saves you a bit of ‘pump time’.
  3. Remember that your front and rear tyres may need different pressures. Check what they should be before you start the pump.
  4. Go round the vehicle with the pump, checking the pressure on each wheel and inflating/deflating as needed. (If you’re not sure how to operate the air machine, they usually have instructions on the front – or ask.)

Remember to have a good look at your tyres as you are inflating them and check for any uneven wear, bulges in the sidewalls of cuts to the tyre. If you find any of these, take your car to a garage or tyre centre to get them checked.

Don’t get confused between the two ways of measuring tyre pressure – PSI and BAR. Both are widely used – here’s how to tell them apart:

Tyre Inflation Guide - PSI and BARTyre pressures in PSI always have two digits – e.g. 28psi.

Tyre pressures in BAR will always be a single digit, probably with some decimal points e.g. 2.65 bar.

Here is a basic PSI – BAR tyre pressure conversion chart to get you started.


PSI
BAR
20 1.45
25 1.75
30 2.10
35 2.40
40 2.75