Drivers are being told about a costly petrol and diesel mistake during heatwaves.

Hot weather has arrived in earnest this week and Brits in parts of England are set to sizzle in conditions of up to 34C this weekend, after the UKHSA and the Met Office issued a 'heat health warning' set to amber level.

That means there is a risk to life due to the hot weather, which has already arrived but is expected to continue to get hotter and hotter throughout the weekend until it begins to cool again on Sunday, June 22.

But drivers may not realise that the heatwave poses another, unexpected problem to do with your fuel tank which could catch you out.

During a heatwave, your petrol - or diesel - actually runs down more quickly than normal.

This is because cars use more fuel during hot conditions, so your fuel gauge may actually become inaccurate and not give a proper indication of how much petrol or diesel you have left.

Experts at PassMeFast.co.uk said: "When it comes to topping up the petrol in your car, there are two kinds of people: those who refill as soon as the fuel tank gets to around 1/4 full, and those who are happy to drive around with the fuel warning light on.

"The thing is, when the weather's nice and warm, your car's fuel levels drop a lot quicker than usual. This means you can't rely on your normal estimations of how much time you have left before needing to fill up."

"To avoid getting stuck in the middle of nowhere, or at the centre of a traffic jam on a hot day (both nightmare scenarios), make sure you head to the petrol station in good time. Playing it close to the line is just not worth it if the sun's out!"

Drivers have also in the past been told not to fill up their car during hot conditions due to a risk of the vehicle 'exploding' in the sun.

Thankfully, this is not a real problem and is in fact a myth.

Rod Dennis, RAC spokesperson, said: "There is no truth in this.

"All fuel systems on passenger vehicles are designed to cope with any expansion of fuel, or vapour coming from the fuel.

"There is no risk of explosion from filling up a fuel tank fully and drivers should have no concerns in doing so."