Tyre Pressure: Why It Matters More Than You Think

Under-inflated tyres are one of the most common and easily preventable car problems. When a tyre doesn't have enough air, it flexes more than it should as it rolls. This extra flexing generates heat — and heat is the enemy of rubber. It causes accelerated wear on the outer edges of the tread, reduces fuel efficiency, and can ultimately lead to a tyre blowout.

Studies show that a tyre just 20% under-inflated can reduce fuel efficiency by around 10% and cut tyre life by 20%. For most drivers, that means spending significantly more on both fuel and tyres every year simply because they're not checking their tyre pressure regularly.

While under-inflation gets most of the attention, over-inflated tyres carry their own risks. When a tyre is over-inflated, it becomes more rigid and a smaller contact patch touches the road. This reduces grip and makes the car more susceptible to aquaplaning. It also means the tyre is less able to absorb road imperfections, making impacts — like potholes — more likely to cause damage to the tyre or wheel.

An over-inflated tyre will wear more quickly through the centre of the tread, while the edges remain relatively unworn. If you notice this pattern on your tyres, it's a strong indicator you've been running too much pressure.

The correct tyre pressure for your vehicle is set by the manufacturer and can be found in the owner's manual, inside the driver's door jamb, or on the inside of the fuel filler cap. Note that many cars require different pressures for front and rear tyres, and some specify higher pressures when the car is fully loaded.

Tyre pressure is measured in PSI (pounds per square inch) or BAR. Most UK cars run somewhere between 28 and 36 PSI, but always check your specific vehicle's recommendation. Never use the maximum pressure printed on the tyre itself — that's the maximum the tyre can hold, not the pressure your car needs.

We recommend checking tyre pressure at least once a month and always before a long journey. Tyre pressure changes with temperature — tyres lose roughly 1 PSI for every 10°F (5.5°C) drop in temperature, which is why pressure checks are especially important in autumn and winter.

Always check pressure when the tyres are cold — ideally before you've driven more than a mile. Driving heats the air inside the tyre and increases the pressure reading, which can give you a falsely high reading and lead to under-inflation.