With the UK set to experience temperatures up to 28°C this weekend, motorists might be tempted to crank up the air conditioning to keep themselves cool. However, this and other hot weather driving habits could lead to increased fuel consumption, experts have warned.
How to Save Fuel in Hot Weather
Tim Rodie, resident car expert at Motorpoint, explained: “When driving in hot weather, it might be tempting to drop the windows and crank up the air conditioning to full blast, but this will ruin your fuel economy. There are a couple of things you can do to reduce your fuel consumption and help you go longer between filling up.”
Rodie advises using the ‘recirculate’ function on your dashboard: “It’s widely known that air-con uses a lot of energy and can increase your fuel consumption by up to 10%, especially when it’s cooling warm air coming into the cabin. Instead, if you use the ‘recirculate’ function, it’ll cool the air already in your cabin and recirculate it – this can reduce energy usage and help to cool your cabin using less fuel.”
Before starting your journey, ventilate your vehicle for a few minutes to let hot air escape. “This will save you having to cool down a hot vehicle when you begin driving and allow your cabin to cool down quicker,” Rodie added.
Windows and Speed
Rodie also shared the rule on windows: “When you’re approaching a motorway, this is the best time to close your windows. Even though a cool breeze on the road is a great feeling, open windows at high speeds can impact the aerodynamic performance of your car, making it work harder to keep up to speed and cause it to use more power and fuel. By setting the aircon to ‘recirculate’, it'll help keep the cabin cool without a significant hit to fuel economy. So, if you’re driving above 50mph, keep the windows up and rely on your air conditioning for the duration of the journey.”
If you're tempted to cool the car down before a journey, don't. Rodie said: “It's recommended to not leave your car running to cool down before starting your journey on a hot day, because idling is terrible for fuel efficiency. Even more importantly, leaving it unattended with the engine running massively increases the risk of it being stolen. Most car insurance policies have ‘keys in car’ or ‘vehicle left unattended’ clauses that mean motorists aren’t able to make a claim if their vehicle is stolen while unattended with the keys inside. Modern air-conditioning will cool your vehicle down quickly, so there isn’t really a need to let your car cool down before starting your journey.”
Other Fuel-Saving Habits
Maintain Smooth Driving
“By keeping your acceleration and braking smooth, you can reduce excess fuel consumption and wear and tear on your vehicle, which can help save you money over time. In manual cars, ‘short shifting’ earlier in the rev range can help reduce the strain on your engine and overall fuel use too – try changing up at 2,000rpm when accelerating gently. If you have cruise control, use this to maintain a steady and consistent speed. Driving at the same speed for longer periods of time, where you can, can improve your fuel efficiency by up to 6%.”
Combine Journeys
“It’s not common knowledge that shorter journeys can use more fuel. To save energy, particularly when it’s warmer and you’ll be using more energy for air-con, combine a couple of shorter trips into one by planning errands ahead.”
Heatwave Essentials
“When temperatures are hitting the high twenties, the risk of dehydration is increased, especially if you’re on the road with limited breaks and no provisions in the car with you. Before you set off, make sure you're stocked up with lots of water, sun cream, snacks and other essentials just in case there’s limited stops or if you breakdown.”
