By ensuring your car's tyres are kept inflated to the manufacturer's recommended tyre pressure levels, you can extend the life of your tyres, improve the handling of your vehicle, and maintain the optimum fuel efficiency.
Tyres which are over or under inflated will affect the handling of your car and may cause the tyres to overheat. This will cause your tyres to wear out quicker than if you had kept the pressure at the correct level.
Where do I find the tyre pressure for my car?
This information can be found in the user manual of the vehicle but is also usually printed on a sticker located inside the drivers door jamb. Failing that you can also look up your tyre pressure online although be aware that no website will take responsibility for giving you the correct tyre pressure for your vehicle so if you are not sure then take it to a garage.
If you over fill your tyres the handling of the car will be compromised as the tyres has to swell to take in the extra air. Overinflation actually has the effect of reducing the contact area where the tyre touches the ground.
Increasing the tyre inflation without increasing the load in the car will reduce the vehicle handling most significantly in corners. The optimum tyre pressure is normally the one designated by the car manufacturer.
A few years ago there were stories about how you could overinflate the tyres of your car and gain some fuel economy but the prospect of losing any handling of your car certainly outweighs any fuel economy benefits.
Michelin has previously stated: "[Our] recommendation is, and always has been, that the correct and only inflation pressure for your vehicle is that which is specified by the OE vehicle manufacturer, either on the placard (inside the driver's door jamb) or owner's manual."
Overinflated tyres will wear in the centre more than any other area.
Underinflating your tyres will mean you use up more fuel and increases the tyre wear and tear as more of the tyre is in contact with the ground. Driving with your tyre pressures set 10% lower than the recommended level will increase the fuel consumption by up to 5%. The tyres themselves will wear out up to 30% faster than if you had kept them at the right level.
Underinflated tyres will wear on the edges more than any other area.
When should I check my tyre pressures
You should check your tyre pressures at least twice a month and definitely before a long trip. The best time to check your tyres is when they are cool.