I found this button to de-fog vehicles - but drivers could burn ‘20 percent’ more fuel

A simple car hack could help drivers de-fog their cars in minutes but motorists risk using up more petrol and diesel.

By Luke Chillingsworth, Cars Reporter

I found this button to de-fog vehicles - but there's a catch

Motorists could de-fog their car windscreen quickly without using heating controls by following a basic tip this and . But motorists following the tip run the risk of using up more and in a blow to family finances. 

Last week, I stumbled across a post urging drivers to follow one tip to roll down car windows without starting the engine.

Curious as to whether this would work on my car, I quickly grabbed my keys and headed outside to try the unique solution.

Experts claimed pressing down the car’s unlock button on the key fob for two seconds will see the windows open.

Holding down the button, my Alfa Romeo MiTO let out a small beep but seconds later the window began to descend.

car button de fog fuel

Holding down the button will open the car windows (Image: Luke Chillingsworth)

According to the RAC, pulling down car windows can help drivers clean their screens of fog if they don’t have a climate control system.

Cold air from the outside can reduce the amount of water vapour inside the vehicle which will stop the glass from stealing up.

Tim Alcock, spokesperson for LeaseCar warned the hidden feature” may vary on every model. He told Express.co.uk: “Many car models have a hidden feature built within the key fob that is unknown to most drivers.

“Standing outside your vehicle, hold down the unlock button on your car keys and the windows will start to unwind.

car windows de fog

The window was opened in just a few seconds (Image: Luke Chillingsworth)

de mist car window

Opening the window a fraction can help de-mist car windows (Image: Getty)

“Some cars may differ - so try holding down the unlock button once, releasing it, and then pressing down again to activate this remote feature."

Ford revealed owners could follow the hack to open their windows and the sunroof on most of their models.

They said: "Your vehicle may have a feature that lets you open or close your windows with your key fob and can help you cool the inside of your car before you get in.

"To open all of your windows at once and then the sunroof press and hold the unlock button on your key fob for at least three seconds. If you want to stop them from opening just press the lock or unlock button again.”

However, forgetting to pull the windows up after glass has been cleared could be disastrous with petrol and diesel owners at risk.

According to experts at Leasing.com, leaving the windows wide open at higher speeds can increase fuel use by as much as 20 percent.

Specialists at Schaefer Autobody Centers said opening windows massively increases the drag applied to your vehicle

This has an impact on the chassis and will slow cars down. This means vehicles will need to work harder to reach speeds and will therefore use more fuel.

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