Correct tyre pressure is vital to your safety on the road. Under-inflated tyres affect handling and grip, potentially causing irregular or unpredictable vehicle behaviour. They are also much more likely to suffer from a dangerous sudden rapid deflation, especially on high-speed motorway journeys.
By keeping your tyres at their optimum pressure, your running costs are also reduced. Under-inflated tyres require a bigger force to make them turn, so your car uses more fuel. Additionally, tyres which are not set to their correct pressure wear out more quickly.
So, to benefit from lower fuel bills, longer tyre life, increased safety and reduced CO2 emissions, make sure you check your tyre pressures at least once a month and before a long journey.