Drivers warned over costly petrol mistake you could make during UK heatwave

Motorists are being cautioned about a potentially expensive error with their petrol and diesel[1] during the scorching weather spells[2]. As the mercury soars to highs of 30C this week, following a 'heat health warning' issued at yellow level by the UKHSA and Met Office, Brits are set to swelter under the blazing sun. The alert signifies a serious risk to health from the soaring temperatures, which have already made their presence felt and are forecasted to intensify as the week progresses.

However, drivers might be unaware of an additional heatwave hazard related to their vehicle's fuel tank that could take them by surprise. In the blistering heat, your vehicle's petrol or diesel consumption can accelerate more rapidly than usual, reports the Express[3]. This is due to cars expending more fuel in hot conditions, leading to potential inaccuracies in fuel gauges and misleading readings on how much petrol or diesel remains. experts have advised: "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." They added: "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 previously been warned against topping up their cars during periods of searing heat due to alleged risks of vehicles 'exploding' in the intense sunlight.

However, this has been debunked as a myth. RAC spokesperson Rod Dennis clarified, "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."


  1. ^ petrol and diesel (
  2. ^ scorching weather spells (
  3. ^ the Express (
  4. ^ Rules of driving on hay fever medicine (