Your tyres are the only contact patch between your car and the road surface. Incorrect tyre inflation not only dramatically reduces fuel economy through increased rolling resistance, but also degrades steering responsiveness and increases stopping distances in emergency situations.

The Real Cost of Under-Inflated Tyres

When a tyre is under-inflated by just 5 PSI (0.34 bar), rolling resistance increases by over 10%, translating into a 2% to 3% drop in overall fuel efficiency. Over a year of average UK mileage (7,400 miles), under-inflated tyres can needlessly cost a driver between £50 and £120 in wasted petrol or diesel.

How to Check Tyre Pressures Correctly

Follow these key guidelines when measuring your tyre pressure:

• Measure when tyres are cold: Driving warms up the air inside the tyres, causing pressure readings to rise by 2 to 4 PSI. Always check before driving or after the car has rested for at least an hour.
• Check the manufacturer placard: Correct pressures (PSI / Bar) are located inside the driver's door jamb or inside the fuel filler flap, NOT the maximum rating embossed on the tyre sidewall.
• Adjust for heavy loads: If you are embarking on a family holiday with luggage, increase tyre pressures to the recommended "laden" specification.
• Don't forget the spare tyre: Check your space-saver or full-sized spare every few months so you aren't stranded when you need it most.

UK Legal Tread Depth & Wet Grip

The UK legal minimum tyre tread depth is 1.6mm across the central three-quarters of the tyre. However, wet braking efficiency begins declining rapidly below 3.0mm. Perform the 20p test: insert a 20p coin into the tread grooves; if the outer band of the coin is visible, your tread is approaching the legal safety threshold and requires immediate replacement.