Little-known reason you should check your tyres in heatwave weather

As temperatures soar to as high as 32C in some parts of the UK this week, motorists are being advised to carry out additional maintenance checks.

London experienced a peak temperature of 32C on Thursday and with many areas seeing very hot weather as well as thunderstorms, it's crucial to ensure your vehicle is equipped to handle these varied conditions. Specifically, drivers should check their tyre pressure is suitable for the weather.

This is due to the fact that extreme temperatures can alter the pressure within tyres, subsequently impacting fuel efficiency, steering control, and braking distance. Moreover, obtaining an accurate reading of your tyres' pressure under such conditions could prove challenging.

How heat can affect your tyres

When tyres become excessively hot, the gas inside them expands, leading to increased pressure. If this results in over-inflation, your subsequent journey may feel considerably rougher as the tyres lose flexibility and struggle to absorb road surface irregularities effectively.

This could affect the safety of your drive as overinflated tyres have less contact with the road, providing less overall grip. If you need to brake abruptly while your tyres are overly pressurised, you may find that it takes longer than anticipated, thus heightening the risk of an incident.

Long-term use of overinflated tyres might also lead to higher expenses down the line due to them wearing out faster, reducing their ability to grip the road and necessitating earlier replacement.

How to take a precise pressure reading

Ensure tyres are cool

Taking an accurate reading of your tyres' pressure isn't as straightforward as simply removing the dustcap and using a pressure gauge meter. If the tyres are already hot, such as from extreme heat or a recent drive, then you may get an inaccurate reading due to the expansion of gases.

Instead, it is generally recommended to take a reading when the tyres are cool. Ideally, this would be before the car embarks on a journey or at least a few hours after returning from a journey to allow the tyres to cool down.

Once you've taken a reading of each tyre and you're confident it's accurate, you can either inflate or deflate them according to the vehicle manufacturer's recommendations.

How to read your tyres' pressure

Tyre pressure is typically measured using two standardised systems: bar and pounds per square inch (PSI). Digital gauge readers usually offer the option to switch between these two measurements.

However, if you're using an analogue reader that only provides one measurement, you can convert the readings with the knowledge that one bar is equivalent to 14.5 PSI.