UK motorists are being warned to top up their petrol and diesel tanks ahead of the Bank Holiday weekend as the country braces for a record-breaking heatwave. Temperatures are forecast to hit 34C in London on Monday and Tuesday, before dropping back to around 23C on Wednesday. Experts say the combination of soaring heat and busy roads could increase fuel usage unexpectedly, leaving drivers short or stuck in traffic.
Heat and Fuel Efficiency
High temperatures can affect fuel use in multiple ways. Warmer engines reach optimal operating temperature faster, summer-grade petrol contains slightly more energy, and warm air reduces aerodynamic drag, all of which could improve efficiency. However, driver behaviour often offsets these gains.
Rolling down windows or using air conditioning extensively can reduce fuel efficiency by up to 25%, particularly on short journeys. For hybrids and electric vehicles, the effect can be even more significant. As the roads fill with holiday traffic, cars may burn more fuel idling or moving slowly in congestion.
Hot conditions can also make fuel gauges less accurate, increasing the risk of drivers misjudging how much petrol or diesel remains. Experts advise filling up early to avoid being stranded and to mitigate higher costs due to unnecessary fuel consumption.
Rising Petrol and Diesel Prices
The warning coincides with already high fuel prices. The average unleaded petrol price now stands at 158p per litre, while diesel has reached 185.5p per litre, partly driven by global supply disruptions linked to the Iran conflict. With prices at these levels, drivers are being urged to plan ahead to avoid paying more during the hottest days of the year.
Safety Myths
Some motorists worry about filling up in hot conditions, fearing the fuel might ignite. RAC spokesperson Rod Dennis said modern vehicles are designed to handle fuel expansion and vapor safely. Drivers can fill their tanks without risk of explosion, though maintaining engine efficiency in extreme heat remains important.
Tips for Drivers
Experts recommend topping up early, minimizing air conditioning during short trips, and monitoring fuel levels carefully. According to Fuel Finder UK, optimal fuel efficiency occurs at temperatures between 15C and 20C, with efficiency dropping sharply as temperatures rise above 30C. Keeping these tips in mind can prevent stress, ensure safe travel, and avoid unnecessary fuel costs.
With temperatures expected to peak over the Bank Holiday weekend, careful planning, awareness of fuel usage, and timely refills are essential for UK drivers aiming to enjoy their holiday while avoiding costly surprises at the pump.
