Bridgestone is reminding drivers not to respond to higher pressures when the tyre is warm by letting air out. It says pressures need to be checked when the tyre is cold, at ambient temperature and ideally in the mornings.
After the car has been driven for a while and the tyres warm up the pressures will go up and the air inside gets hotter too and starts to expand. This is perfectly normal but Bridgestone says some drivers are checking when the tyre is warm, seeing the higher pressures and letting air out to compensate but warns that this will only reduce cold-running pressure leading to reduced grip and handling, prematurely wear the tyre and increase fuel bills.
A spokesman said: “When the temperature rises, so does your tyre pressure when driving. Remember to check the pressure when the tyre is cold. If you want to rely on its full road performance, then check its pressure in the morning.
“During your ride, heat will build up inside the tyre and because of this, the pressure will rise as well. That’s perfectly normal, don’t worry. So, what you should definitely not do is lower the pressure of a hot tyre. When the tyre cools down, the pressure drops automatically. If you have lowered the pressure you risk getting under the prescribed minimum pressure when the tyre is cold.
“Your tyre’s life is in the hands of its pressure. If the pressure isn’t right, your tyre will wear down faster. If you see the sides of the tread pattern wearing off, that might be an indication that your pressure is too low. If only the very middle of your tread pattern is wearing down, your tyre pressure probably is too high. Both are safety hazards you want to avoid.
“If you have a lower tyre pressure, finally, you will also increase rolling resistance and waste more fuel. So, driving with the right pressure will be better for your fuel economy, and will save you money on the go.”
Bridgestone has produced a video showing how and when tyre pressures should be checked. Click here to watch it.