Drivers warned to avoid one button as it ‘increases fuel consumption by 20 percent’. (Image: Getty)
With temperatures finally starting to climb and fuel costs remaining high, many motorists will be seeking ways to stay comfortable while improving their fuel economy.
When driving in warm conditions, motorists typically choose between having the windows down or activating air conditioning.
While many may underestimate their effect on fuel efficiency, both alternatives have a significant impact on consumption patterns.
Air conditioning is extremely energy-intensive, while open windows can heighten the vehicle’s drag, forcing the car to work harder and consume fuel more rapidly.
While both options can be employed, there are circumstances where one proves more advantageous to the driver and vehicle.
Chris Evans, head of content at Leasing.com, emphasised the advantages of utilising both air conditioning and having the windows open.
Using the air con can increase fuel consumption by 10 percent. (Image: Getty)
He cited a 2004 study by the Society of Automotive Engineers (SAE), which examined the impact of windows open versus air conditioning in larger saloons and SUVs.
The study incorporated numerous variables, including the extent to which windows were open, the aerodynamics of various vehicles and the duration of air conditioning use.
He said: As such, the 45mph 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.”
Several additional studies have since emerged, one of which established that hybrid vehicle fuel economy is more severely affected by air conditioning use than conventional combustion-only cars.
How to save money on fuel. (Image: Express)
Further research, conducted by Emissions Analytics, revealed that the impact of air conditioning on hybrid fuel economy was nearly double that of standard vehicles.
Fuel efficiency fell by 6.1 percent in a hybrid car on average, compared to just 3.8 percent for a standard petrol car and 4.6 percent for a diesel.
Mr Evans went on to say: “While the 45mph line is a good guide, things get a bit more complicated when you are in bumper-to-bumper traffic.
“In these situations, it is probably best to avoid using air con or opening your windows.
“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.”
Alternative methods for maintaining a cooler vehicle without depending on air conditioning include finding shade or garage parking.
Tinted windows may also offer advantages for motorists, alongside heat deflectors.
A car window tint can successfully cut the heat produced by direct sunlight by up to 70 percent within a vehicle.
As the vehicle will remain cooler, motorists may be less inclined to activate the AC.