If you wake up one morning and get in your car to notice that your tyre pressure is low, especially when it has happened to all four tyres, cold weather is likely the culprit.

Depending on the time of year and where you are located, seasonal temperature fluctuations can cause noticeable swings in your tyre pressure. This often comes as a surprise to drivers, particularly those who have recently topped up their pressure to the required level.

Unfortunately, there is little that can be done about this. As you’ll remember from school chemistry classes, gasses expand when heated and contract when cooled. So if you inflate your tyres to the require level when the ambient temperature is 15° Celsius, a temperature drop of 5-10° can cause a significant drop in your tyre pressure, sometimes enough to trigger your tyre pressure monitoring system.

How to deal with fluctuating external temperatures?

There are three key priorities when it comes to looking after your tyres:

  • Maintaining grip and performance to ensure you’re safe and in control on the road.
  • Maximising the life of the tyre by minimising unwanted friction
  • Achieving optimal fuel efficiency to minimize costs.

In order to achieve these goals, your tyre pressure should be adjusted as required to remain at the recommended level. So at times of year when the temperature swings are more dramatic, pressure levels should be monitored and adjusted more frequently.

You might be wondering whether letting the pressure levels drop a bit will really cause that much of a problem, and considering waiting for the external temperatures to rise again.

However, it’s highly recommended that you do proactively ensure your pressure levels stay within the recommended range. Tyre pressures have a direct effect on the performance and control of your vehicle. Slightly reduced pressure can lead to diminished handling and traction, and reduced braking control. The risk are even higher when you’re carrying a heavy load.

How much will temperature affect my tyre pressure?

A general rule of thumb is that every 5° fluctuation in outside temperature will cause a 1 PSI reduction in tyre pressure. So if temperature drops from 20° to 5°, PSI will likely decrease by approximately 3 PSI.

Increased external temperatures

If your tyre pressure level is set when outside conditions are cold and temperature increases, you could end up with over-inflated tyres. Like with cold temperatures, hot temperatures will increase tyre pressure by approximately 1 PSI per 5° Celcius. The problem with this scenario, however, is that tyre pressure monitoring systems generally don’t alert you to over-inflated tyres, meaning you can end up driving around on them for a long time before realising.

Similar to under-inflation, over-inflation has a negative impact on handling, performance, and the life span on your tyres.

The best way to deal with fluctuating temperatures

The only way to ensure your tyres are always at the recommended temperature and you’re always in full control of your vehicle is to make tyre pressure monitoring a routine maintenance task, just like changing your oil or topping us brake and wiper fluid.

But don’t pay to use the petrol station forecourt each time. Grab yourself a Pitstop tyre pressure gauge to check your pressure level without even needing to leave your home.