How can I check my tyre pressures?
We show you how to find the correct tyre pressures for your car, how to check your tyre pressures and show you our tyre inflator picks
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Almost as important as the tyres themselves, correct tyre pressures save fuel, give you maximum grip and keep you safe. Here’s how to check yours.
It might be just one of those dull tasks on your to-do list that you never get around to, but the reality is that keeping your tyre pressures at the correct level is an all-round win. Tyres set to incorrect or uneven pressures wear out more quickly, use more fuel, don’t offer as much grip and braking performance and are more likely to fail or blow-out - which should be more than enough reasons to keep them checked.
How do I check my tyre pressures?
1. Make sure you know the correct tyre pressures for your car before starting (details of how to find this data are below).
2. To accurately measure the current pressure in your tyres you can use a handheld pressure gauge, a portable tyre inflator or an inflator at a fuel station or garage.
3. As tyre pressures rise slightly when the tyres are warm it is best to check them before a journey if possible.
4. Remove the dust cap from the tyre valve and push the connector firmly on - this should then give you a reading on the measuring device.
5. If you’re using an automatic device you simply set the tyre to the desired pressure and it will inflate until the correct reading has been achieved - and don’t forget to replace the dustcaps afterwards.
Converting Tyre Pressure In BAR to PSI
Tyre pressures are almost always expressed as PSI (then BAR). However, some compressors and inflators are in BAR. The chart below converts pressure in BAR to PSI.
| BAR | PSI | BAR | PSI | BAR | PSI | BAR | PSI | BAR | PSI |
| 1.30 bar | 17 psi | 1.90 bar | 27 psi | 2.60 bar | 37 psi | 3.25 bar | 47 psi | 3.95 bar | 57 psi |
| 1.35 bar | 18 psi | 1.95 bar | 28 psi | 2.65 bar | 38 psi | 3.30 bar | 48 psi | 4.00 bar | 58 psi |
| 1.40 bar | 19 psi | 2.00 bar | 29 psi | 2.70 bar | 39 psi | 3.40 bar | 49 psi | 4.10 bar | 59 psi |
| 1.45 bar | 20 psi | 2.10 bar | 30 psi | 2.75 bar | 40 psi | 3.50 bar | 50 psi | 4.15 bar | 60 psi |
| 1.50 bar | 21 psi | 2.15 bar | 31 psi | 2.80 bar | 41 psi | 3.55 bar | 51 psi | 4.50 bar | 65 psi |
| 1.55 bar | 22 psi | 2.20 bar | 32 psi | 2.90 bar | 42 psi | 3.60 bar | 52 psi | 4.80 bar | 70 psi |
| 1.60 bar | 23 psi | 2.25 bar | 33 psi | 3.00 bar | 43 psi | 3.70 bar | 53 psi | 5.20 bar | 75 psi |
| 1.70 bar | 24 psi | 2.30 bar | 34 psi | 3.05 bar | 44 psi | 3.75 bar | 54 psi | 5.50 bar | 80 psi |
| 1.75 bar | 25 psi | 2.40 bar | 35 psi | 3.10 bar | 45 psi | 3.80 bar | 55 psi | 5.85 bar | 85 psi |
| 1.80 bar | 26 psi | 2.50 bar | 36 psi | 3.20 bar | 46 psi | 3.90 bar | 56 psi | 6.20 bar | 90 psi |
What are my tyre pressures?
There’s no point in checking tyre pressures if you don’t have the right information in the first place, so it is worth taking the time to check. Start by checking the labelling on the side of your tyres; the letters and numbers give the tyre dimensions. It’s important to start here because one model of car can wear several different tyre sizes, so make a careful note of the information which should look something like this: 195/65 R15 91H.
The tyre pressure information for your specific car may be displayed in a number of places; on the B-pillar of the driver’s door or inside the fuel filler flap are the most common locations but the information will also be repeated in the handbook. Pressures for all the tyre sizes available for your car will be displayed, so check this against the specific information you noted down earlier. Many manufacturers also provide a set of different pressures depending on the vehicle load; all of these pressures will be safe for your car to use but it is best to choose the recommended levels, and don’t be tempted to mix pressure levels front to rear - this could upset the balance of your car considerably.
If you can’t find the relevant information in your vehicle you can search out the correct pressure via the manufacturer’s website or one of a number of independent websites such as www.tyre-pressures.com, https://www.tyresafe.org/check-your-pressures/ and https://www.oponeo.co.uk/advice-and-tips/tyre-pressure. If your vehicle is fitted with aftermarket wheels and tyres that don’t match the original specification you should contact the tyre manufacturer for recommended pressures.
What are tyre pressures measured in?
The most common tyre pressure measurements are the imperial PSI (pounds per square inch) or the metric Bar, although some vehicles including some Mercedes-Benz models will display them in kPa (kilopascal) which is also a metric unit. If you need to convert between them, 15PSI is equivalent to 1 bar and 103kPa.
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