Tyre Inflation Guide
Are Your Tyres Correctly Inflated?
Even if your tyres look correctly inflated, they may well be under or over inflated:
- Up to 2 pounds of air escapes naturally every month, even without a puncture.
- Tyre pressures are affected by temperature (e.g. summer vs. winter temperatures)
- Wear and tear and slow punctures can cause the pressure to fall without you noticing.
Incorrectly inflated tyres are both dangerous and a waste of your money. They wear out faster and provide poor handling performance when compared to correctly inflated tyres.
How Do I Know What Tyre Pressure My Car Needs?
Every car has different recommended tyre pressures and they are often different for the front and rear wheels.
To find out what tyre pressure is required for your car's tyres, you should look in the owner's manual for your car. Check the recommended tyre pressures for your model.
Inflating Car Tyres - How & Where
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. Realistically, this isn't always a very practical approach, especially if you do not have your own foot pump and tyre pressure gauge to use at home.
A more realistic approach is to check your tyres at a garage close to your home or perhaps use a supermarket garage 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 will be cold.
This will give an accurate reading and will enable you to use the garage's air pump and pressure gauge, which are usually more powerful and easier to use than portable ones.
Here's how to do it:
Pull up to the pump so that the air hose will reach all four of your wheels without you needing to move the car.- 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'.
- Remember that your front and rear tyres may need different pressures. Check what they should be before you start the pump.
- 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: 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 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 |
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