Before we address if tyres should be inflated passed their recommended PSI, let’s tackle what PSI stands for and what it is!
PSI stands for: Pressure per Square Inch and indicates how much air you should have in your tyres to effectively support your vehicle.
It is recommended that your cars PSI is checked weekly; especially in the colder months, as the fluctuating temperate of the tyres (as you drive) and the weather can alter the pressure within the tyres.
You can find out your vehicles recommended PSI is by checking the vehicles handbook or by typing your registration into the following website: "Find your vehicles recommended PSI here"
What happens if I inflate my tyres passed the recommended PSI?
While you are driving the motion between the cars tyres and the ground causes intense friction (allows the car to grip the road). This friction causes the air inside the tyres to heat up and with anything that heats up, it begins to expand. If you over-inflate your tyres to the maximum PSI (or just below the maximum PSI) there will not be enough room for the heated air to expand. The air will expand anyway and could therefore cause a blowout.
Also, when you over inflate types (beyond their recommended PSI) the tyres become hard. This means that less of the tyre is in contact with the road surface giving a decreased grip which could also lead to an accident due to lack of control over the vehicle. Because less of the tyre would be in contact with the road, the part that is in contact with the road (usually the middle of the tyre) will wear out quicker meaning the tyres will need to be replaced sooner than usual if they stay over inflated.
To conclude, although over inflating your tyres can give you a better fuel mileage it can potentially be very dangerous so it’s always best to follow the owners guide or professional advice and inflate your tyres to the recommended PSI.