Drivers are using car air con incorrectly as UK heatwave continues

Motorists could be using their air conditioning incorrectly, putting road users at risk of burning through petrol and diesel fuel this summer. Road users are likely to reach for their air conditioning buttons in a searing heatwave, with temperatures continuing to rise this week.

The chance of grabbing some cool air while sweating in a roasting cabin could be difficult to resist, but road users may not be aware that the move could backfire. Air con units are likely to take some time to start cooling effectively in hot weather, meaning the system may only be up and running by the end of a short journey. Those getting behind the wheel to drive around town may end up burning through fuel to use the system for little benefit.

John Wilmot, CEO of LeaseLoco.com, stressed that individuals should be aware of this simple issue before making a grab for the button.

John said: “When you turn the AC on in your car it can take a while for the system to get going because it needs to make the refrigerant cold. This is the fluid that is used to cool the air.

“Once the fluid is cool, it’s then blown through the vents to cool the car down, but replacing all of that warm air can take some time. It can take even longer if your car has been parked in the sun previously.

“This makes your car hotter and means the air conditioning has to work even harder in cooling the car dow,n which is why it’s best to park in the sun or use sunshades.

“If you’re on a short journey and you're driving under 40mph, you’re actually better off just opening the window to cool down rather than waiting for the aircon to kick in. It’ll be much more efficient and you won’t be using any more fuel.”

KwikFit has previously warned that air conditioning was likely to increase fuel consumption by between 8% and 10% on average.

Meanwhile, temperatures are expected to soar this week as the UK continues to bask in a heatwave.

The Met Office has predicted temperatures could rise to 30 Celsius in London on Friday and 31 Celsius on Saturday.

However, John has revealed it may be better to switch on the air con if motorists are heading for longer trips at higher speeds.

He said: “If you’re driving in an area that exceeds 40mph then you’ll want to switch to using air conditioning.

“Driving at higher speeds with your windows open can create a drag which will make your engine work much harder and will ultimately cause your car to use more fuel.”