Your tyres are your only contact with the road and affect the steering, braking and direction of your vehicle.

Tyres also need to perform the functions of carrying the load, cushioning, rolling and lasting.

Steering

Tyres should steer the vehicle with precision, whatever the condition of the surface. Ensuring that the tyres are inflated to manufacturers recommendations in both the front and rear can aid directional stability.

Carrying the load

A car tyre carries more than 50 times its own weight and must be able to support the vehicle not only when it is moving but also when the vehicle is stationary.

Cushioning

Tyres cushion the vehicle from shocks caused by obstacles and surface irregularities which ensures a comfortable ride for both the driver and passengers.

Correct tyre pressures will aid cushioning and give good levels of comfort.

Rolling

When the tyre is in contact with the ground it changes shape. This change of shape uses energy, 25%-30% of the overall rolling resistance comes from changing the shape of the tyres as they roll round.

Under-inflated tyres change shape more as they roll and therefore use more energy.

Durability

Tyres must maintain optimum performance over millions of wheel revolutions and again tyre pressure has a major part to play in this area.

Tyre pressure impacts on the size and shape of the contact patch of the tyre and also the stress distribution of the tyre.

The functions of a tyre guarantee safety, comfort and economy. As stated in all sections above, tyre pressure is vital if the tyre is to maintain optimum performance.