How To Check Your Tyre Pressures

Research undertaken by Protyre on vehicles visiting our centres has shown that 90% of all vehicles that visit our centres have the incorrect tyre pressure – even for tyres that aren’t being replaced.


The RAC Foundation commissioned research which found that 2 million drivers never checked their tyre pressures between visits to a garage.

Tyres by their nature leak, this means that over a period of time they will deflate. The speed of deflation will reduce if Nitrogen is used to fill them however even if they have been filled with Nitrogen they will still lose pressure at a slower rate.

Over inflating your tyres can also have a negative effect on the life of your tyres and under inflation will have an impact on the fuel efficiency of your vehicle, before the possible safety implications of either over or under inflation.

It is recommended that you check your tyre pressures at least once a month and before a long journey or more regularly if you are driving substantial distances on a regular basis.

Checking Your Tyre Pressures

If your unsure what pressure you should have in your tyre it will normally be available in one of three places:

1. Inside the drivers door on the ledge

2. Inside the petrol / diesel cap

3. In the vehicle manual

Alternatively, call your local Protyre and they will be pleased to help.

How to check your Tyre Pressure Gauge

Low cost tyre pressure gauges are available to purchase from most automotive parts and accessories retailers, from Road Safety organisations like the AA or RAC or from some tyre manufacturers like Michelin. You should remember that these may be calibrated when you first purchase them however these will become less accurate over a period of time.

You should always check tyre pressures when the tyres are cold – when the gas in a tyre heats up it will expand and the pressure will change, giving a higher reading.

Remove the dust caps from your wheels – keep these safe and don’t put them onto the ground as this may get dirt into them and onto the threads causing them to become more difficult to screw on and potentially damaging the valve

Attach the pressure valve – check the reading and deflate or use a pump to add additional air as necessary.

When you are satisfied that you have the correct tyre pressure remove the air line from the pump and recheck the pressure.

Replace the dust caps having ensured that no dirt has got into the caps or the air valve.

You may want to check your tyre pressures when you are refueling, most petrol stations have machines in place to do this. However it is worth noting that these may not be calibrated and may not give a completely accurate reading, if in any doubt ask the forecourt attendant when they were last calibrated.

If you have any questions or you would rather have one of our technicians under take a check, don’t hesitate to call into any of our centres and we will be pleased to help.

All reputable garages will be pleased to check your tyre pressures without charge.

Bar v PSI Pressures

Pressures are measure in 2 ways:

1. Bar which is equivalent to 14.5038 PSI.

2. PSI – pounds per square inch

Your tyre pressure may be measured in either scale and tyre pressures are normally shown in both formats. Be cautious do not fill your vehicle to the PSI level if using the Bar scale on your pressure monitor

Tyre Pressure Monitoring Systems (TPMS)

Since November 2012 Tyre Pressure Monitoring Systems TPMS have been legally required on any vehicle sold in the European Union. Many cars sold before this time had TPMS fitted before. TPMS systems work on a range of different systems and should you have a problem a warning light will normally flash on your dash board.

Of course, tyre pressure monitoring systems (TPMS) first appeared in the luxury marques some time ago. In the late 1980s, Porsche 959 models started to feature it, but at first it was confined to these high-end and performance cars. Even in those early days, our tyre professionals were working with these systems, gaining the years of experience that they now use every day, on every kind of vehicle.
Bridgestone, Falken, Pirelli and Sumitomo all produce run-flat tyres, that will continue in service even though pressure has been lost. Our qualified fitters can advise on the use of run-flat tyres with TPMS, and give specific advice for the make and model of car you drive and the type of tyres you want to fit.
Note that a faulty TPMS system, or one that doesn’t work at all, will lead to an MOT failure. The Government’s Driver and Vehicle Standards Agency (DVSA) has a useful reference checklist of the MOT tests [1], including the test for a working TPMS for any vehicle used on or after 01/01/2012.
The Royal Society for the Prevention of Accidents (ROSPA) makes the important point that you need to know how the TPMS will tell you if there is a sudden loss of pressure. So, if you have a new car, make sure you will recognise the light, sound or warning that the TPMS on your model uses to alert you to a problem. If you’re not sure or have any queries, why not call in and ask one of the qualified fitters at your local Protyre garage. We have extensive experience with all types of car TPMS and will be happy to help.

If you do find you have a TPMS warning light you should stop, when it is safe to do so and check that you have not had a tyre failure or major leak of gas from your tyres. You should contact a garage or fast fit centre as soon as possible to ensure there are no problems with your tyres. To find out more about TPMS click here

Protyre offer Free TPMS Checks to all of our customers. Click the button below to book now.

Free TPMS Check

Tyre Pressures are Important

Tyres are your only connection with the road in fact at any time each tyre will only have an area the size of the average palm in connection with the road. Apart from tyres and the pressures been important to safety in correct tyre pressures will have a number of other effect which may be harmful to your pocket.

Uneven Wear

Tyres are built to have as much of their surface in contact with the road as possible. An over or under inflated tyre will wear un evenly reducing the overall wear in one area of the tyre, reducing its lifespan and meaning that it will need to be replaced more quickly.

Tyres that are incorrectly inflated are also likely to be less fuel efficient and are more likely to suffer from either a blow out or other sudden deflation. Get a Free Tyre Check with Protyre for peace of mind and ensure you and your passengers are safe.
Free Tyre Check

Tyre life and How Tyre Pressure affects them

It is very important that a tyre is correctly inflated to get the maximum life out of your tyres. Having the correct tyre pressure helps to make sure that the weight of the vehicle is distributed equally across the tyres tread pattern, this will ensure that the vehicle is at its most stable. When a tyre is under inflated, it will impact the stability of the vehicle and you will also see a negative impact on the handling and cornering of the vehicle. See our article on how to identify the age of your tyres. 

10 Things to Remember About Tyre Pressures 

1. Tyres should be cold when you check tyre pressures – preferably they shouldn’t have driven more than 3 miles

2. Tyre Pressures should be checked at least monthly, more often if you are driving long journeys, or are driving large numbers of miles.

3. Check and change the tyre pressures if you are driving a heavily laden vehicle – always check the hand book or consult your garage

4. Get the correct pressure details from either the vehicle handbook, drivers door ledge or petrol cap

5. Check that any pressure gauge you use is reliable and has been calibrated recently

6. Don’t forget to check the spare when you check your pressures

7. Pressures decrease more rapidly in warmer weather so check more often

8. If you are towing don’t forget to check the pressures on these

9. Use your regular pressure check to check the general condition of your tyres

10. If in doubt consult your garage or fast fit centre or call Protyre

Tips for taking care of your Tyres

1. Make sure you check the pressure regularly
2). Check for damage on a regular basis and any unusual wear and tear.
3). Check your tyres tread. Remember the minimum legal requirement is 1.6mm of tread.
4). Don't overload your car. 
5). When there is extra weight in your car, make sure the tyres are inflated to the recommended levels indicated in the user manual.
6). Maintain good driving habits. 

Tyre Fuel Efficiency 

With the cost of fuel always seeming to be increasing, it is always worth looking for ways to make savings through other areas. Looking at your vehicles fuel consumption is one such way, as using less fuel ultimatley saves money, and various car tyre features can contribute to this factor. Every part of a tyre has the potential to cause a significant increase or decrease in the use of fuel. Please take a look at our article about tyre labelling which explains how different tyre fuel ratings impacts the efficieny of your tyres. 

About the author

David Sholicar

David is the National Retail Operations Manager for Protyre. One of David’s areas of responsibility and ...

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