How Hot Weather Affects Tyre Pressure

When the cold weather hits, many of us start worrying about our tyres. However, fluctuating temperatures at any time of year can alter the air pressure in your car’s tyres. This can impact your vehicle’s road holding, steering performance, braking distance, overall safety, and fuel economy. Additionally, it affects how long your tyres will last and remain in good condition. Thus, keeping an eye on your tyre pressure during warmer weather is crucial for safe driving. In this guide, we’ll explain what to watch for and how to maintain optimal tyre pressure in the heat.

Changing Temperatures and Tyre Pressure

Tyres are essentially composed of pressurised air inside a tube of reinforced rubber. Like any gas, this air expands at higher temperatures and contracts in colder temperatures, affecting your tyres’ pressure. Although road surface friction generating heat can also influence tyre pressure, the main factor is the ambient temperature—the weather.

How much difference does the weather make? As a general rule, every 10°C rise or fall in temperature affects a tyre’s pressure by 1-2 PSI. Therefore, the change in your tyre pressure from summer to winter can be up to a 15% difference, significantly impacting tyre and vehicle performance.

Does Hot Weather Affect Tyre Pressure?

Friction and resistance cause heat build-up inside car tyres. The warming effect of the weather further increases this pressure. However, most tyres are designed with built-in air pressure tolerances. Unless conditions are extremely severe, you can drive in hot weather without changing the tyre pressure, provided you monitor it and watch for signs of overheating.

Remember that the tyre pressure recommended by the vehicle manufacturer is set for cold conditions, so always inflate tyres in the shade and never when the vehicle is still warm from driving.

How to Spot an Overheated Tyre

The dark color and materials of your tyres make them very effective at absorbing heat. If they’re hot to the touch, they’re close to overheating. In this case, it’s crucial to stop driving and let your tyres cool down. While it may seem logical to let some air out of overheated tyres, doing so can result in underinflated tyres when the temperature returns to normal.

Risks of Overinflated Tyres

High tyre pressure significantly increases the risk of a blowout. It also reduces traction because less of the tread is in contact with the road, making your handling less responsive and your journeys less safe. For a more in-depth look, check out our guide to over-inflated tyres.

Check Your Tyre Pressure Regularly

We recommend monthly tyre pressure checks in all weather conditions, even if you’re driving infrequently. In addition to reinflating as needed, take this opportunity to inspect your tyres for any damage. This way, you’ll be aware of any issues before they become serious or dangerous. For a simple guide to inflating tyres, visit National Tyres and Autocare.

Tyre Pressure Monitoring System (TPMS)

Most modern vehicles come with a built-in tyre pressure monitoring system (TPMS). This system uses sensors in all four tyres to provide a visual or audible warning if the pressure is too low. However, TPMS is not always entirely reliable and won’t alert you if the pressure is too high. Therefore, manually check your tyre pressure with a gauge as well. For peace of mind, visit your nearest National Tyres and Autocare, and they’ll check it for you.

Risks of Dangerous Tyres

Every year, dangerous tyres lead to around 5,000 convictions, 900 casualties, and 160 deaths or serious injuries. Additionally, illegal tyres can cost more than the price of a new set: you could face fines of up to £2500 and 3 points on your license per illegal tyre. Furthermore, having illegal tyres in an accident can invalidate your insurance.

Conclusion

Maintaining the correct tyre pressure, especially during hot weather, is essential for your safety and the longevity of your tyres. Regular checks and mindful driving can help you avoid the risks associated with improper tyre pressure. Visit National Tyres and Autocare for expert advice and services to keep your tyres in top condition.