November 25, 2015

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.

20 1.45
25 1.75
30 2.10
35 2.40
40 2.75


  1. what is the tyre pressure of my transit flareside 2496cc, tyre’s are 185 R 14

  2. Purchased 4 new 4 x 4 tyres and asked the tyre company to inflate the fronts to be 26psi and the rears to be 29psi.

    Checked the tyres 3 weeks later and found the following : LH Front 27 RH Front 31
    LH Rear 31 RH Rear 33

    tyre gauges are inaccurate but the man behind the gauge has no interest in my safety , points on my licence etc. I understand that the gauge can be faulty but when each tyre pressure is different words fail me.

    I would point out that this man has over 20 years experience in the trade and can’t read a tyre pressure gauge , accurate or not !

    • Have to say that my experience is that garages and tyre fitting centres very rarely inflate tyres correctly. They just aim for the right ballpark — and sometimes don’t even manage that. The only solution is to accept the inevitable and do it yourself. Not ideal, I know.

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