Former Top Gear and Grand Tour presenter Jeremy Clarkson previously admitted drivers are increasing fuel consumption by up to 5% due to a simple mistake. The TV star stressed opening the car window while travelling could backfire with fuel use set to rise.
Jeremy issued the warning as he attempted an audacious challenge on series four as he took an Audi A8 on an 800-mile round trip. Taking off from London, Jeremy attempted to drive as far as the Scottish capital Edinburgh and return home on a single tank. While heading up to Scotland, he admitted the task was a tall order but stressed there were some tips available to save petrol or diesel.
Driving with the window closed was one of his first hacks, with an open window pane set to cost drivers later down the line.
Speaking behind the wheel, Jeremy said: “There are one or two things I can do to help though.
“You have to make sure the car cuts as smooth a hole as possible in the air. Driving with the window down for instance increases fuel consumption by 5%.”
Driving with open windows can dramatically increase aerodynamic drag on the vehicle.
This extra air resistance becomes a problem at high speeds as the wind begins pushing against the car.
Vehicles are then forced to work harder to keep up, draining a little bit more fuel than if the window was completely shut.
Specialists at PTA Garage Services outlined how leaving car windows open can have an effect on vehicles.
They commented: “Although air conditioning increases your fuel consumption, driving with your windows open can also lead to a reduce in fuel efficiency.
“This is because the air from the window creates a ‘drag’ for the vehicle, meaning the engine must work harder to pull the vehicle due to the resistance created by the open window.”
However, a previous study from the Society of Automotive Engineers (SAE) found that open windows reduce fuel efficiency by around 20% while travelling at just 55mph.
Although experts have stressed that opening windows may be more fuel-efficient than using air conditioning which can use up even more petrol or diesel.