Consumer expert Harry Kind has advised drivers to use a simple dashboard button to reduce fuel consumption during hot weather. Appearing on BBC Morning Live, Kind explained that the air recirculation button, marked with an arrow and a car interior symbol, cuts off outside air and recirculates existing cabin air, making the air conditioning system work more efficiently.
Expert Advice on Fuel Saving
Kind responded to presenter Rav Wilding's query about whether driving with windows open wastes fuel. Kind stated: "If you were driving very fast then keeping your windows down will increase drag. That is bad for your car. If you're going slowly your air con is probably going to use a lot more fuel so it would be worth opening the windows on a hot day through a city to get rid of the hot air inside and if you are going to use air con use the recirculation mode. That will keep the cost down, but ultimately going down the motorway with your windows down - not so great."
How the Recirculation Button Works
The recirculation mode prevents the air conditioning system from being overwhelmed by hot air from outside. Even with the AC off, it helps keep cabin temperatures lower. The RAC advises: "Once the air conditioning is blowing cold, close all the windows and switch to (pre-cooled) recirculated air. You can now open the upper air vents and adjust the flow as required. More advanced 'climate control' air-conditioning systems allow you to set and maintain a constant temperature within the car."
Additional Benefits and Speed Tips
The recirculation button also benefits hayfever sufferers by preventing fresh pollen from entering through vents. Kind further recommended reducing motorway speeds to save fuel. He said: "The Department for Transport says that going down from 80 to 70 miles per hour saves you 25 per cent on your fuel and also it's not illegal. Then when you go down from 70 to 60 that will save you about 9 per cent. The savings get less and less as you get slower and slower." He also advised maintaining consistent speed and using cruise control.
The advice comes as a red Met Office extreme heat warning covers areas from London to Swansea and Somerset to Birmingham, with temperatures potentially approaching the UK record of 40.3°C set in July 2022.
