How many times have you driven into a service station and had the tyre pressures checked and on the attendants recommendation you went with 200 kPa (or 2 bars as it is fondly referred to)? Often to both the front and rear tyres. When we have new tyres fitted on our vehicle (a topic for another day), or have the pressure checked at most tyre dealers, this is almost certainly the pressures that will be used. While this isn’t necessarily wrong, it isn’t exactly correct either.

The motor vehicle manufacturers spend a fortune on design, development and then testing of vehicles before they are put into mass production. During this development and testing stage, they will evaluate different components, with tyres being one of them, and test them under many different and varied conditions, as well as with different tyre pressures.

Ultimately, they will come up with recommended tyres for the vehicle, and these are the ones that would be fitted to the vehicle at the time that it comes out of the plant, and they will also come up with recommended pressures for different conditions.

This pressure will consider things like safety in the form of vehicle handling and tyre temperature build up, to ensure that excessive heat is not generated in the tyres, particularly during high-speed driving, braking characteristics, wear patterns, tyre life, comfort and fuel economy (watch this space, we’ll be chatting about that soon). You will also almost certainly find differing tyre pressure front and rear.

So what do you say to the petrol attendant? The recommended tyre pressures can be written up in a number of places – either in the owner’s manual, the inside of the driver’s side door or in the petrol flap. Do yourself a favour and have a look before next you drive off in your car. It’s also usually depicted in a diagram form for those of us that are slightly technically challenged.

Should you change to a non-approved tyre on the vehicle, or use different tyre pressures to those recommended by the vehicle manufacturer, you will change the handling characteristics of the vehicle and at the end of the day, you could well have a very dangerous condition.

Use the tyre pressures as recommended by the vehicle manufacturer. They have gone to great lengths to come up with pressures that will enable the vehicle to handle in the manner in which they intended.