Drivers warned about button that increases fuel usage by 10%

And as much as you might want to blast your AC at this time of year, experts have suggested to use the button sparingly, as it could increase your fuel usage by up to 10 percent.

Chris Evans, head of content at leasing.com, highlighted the issue while referencing a 2004 study by the Society of Automotive Engineers (SAE) on the impact of windows open vs air conditioning in larger saloon cars and SUVs.

Chris explained that the reason for this is down to increased drag, which requires more power from the engine.

Although the referenced research looked at larger vehicles, other studies have shown that the issue is exacerbated in average-sized cars.

If you're wondering how to avoid a high level of drag, Chris suggested: "The 45mph (70kmph) figure is a guide, but a fairly good one.

“While all this might seem like a minor issue, getting it wrong can have a notable impact on your fuel economy.

“Using AC can increase your fuel consumption by as much as 10 percent but opening the windows at higher speeds can increase fuel consumption by as much as 20 percent."

But while the 45mph rule is a good guide, what should you do if you're in bumper-to-bumper traffic?

"In these situations, it is probably best to avoid using air con or opening your windows," he added.

"However we know that in hot conditions that might be uncomfortable, so as a solution you could turn on the air con but close your air vents.

"The air con merely recycles the cabin air rather than drawing the air from outside, where there is nose-to-tail line of traffic all belching out exhaust fumes."

Motorists could also try tinted windows, which significantly reduce the heat given off by sunlight inside of a car.