With temperatures finally beginning to rise and fuel prices continuing to bite, many drivers will be looking for ways to keep cool while boosting their fuel efficiency. When behind the wheel in warmer weather, motorists generally face a choice between winding down the windows or switching on the air conditioning.
Although many drivers tend to overlook their influence on fuel efficiency, both options carry a considerable impact on how much fuel a vehicle consumes. Air conditioning is notoriously energy-hungry, while open windows can increase the vehicle's aerodynamic drag, making the engine work harder and burn through fuel at a faster rate.
Although both choices have their merits, there are situations where one option proves more beneficial for both the driver and the vehicle, reports the Express. Chris Evans, Chief Marketing Officer at Leasing.com, highlighted the benefits of using both air conditioning and open windows strategically.
Study Reveals Key Speed Threshold
He referenced a 2004 study by the Society of Automotive Engineers (SAE), which looked into the effects of open windows versus air conditioning in larger saloons and SUVs. The research took into account a wide range of variables, including how far windows were open, the aerodynamic profiles of different vehicles, and how long the air conditioning was in 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."
Impact on Hybrid Vehicles
A number of additional studies have since been published, with one finding that air conditioning has a greater impact on fuel economy in hybrid vehicles than in conventional petrol or diesel cars. Further research carried out by Emissions Analytics revealed that the effect of air conditioning on hybrid fuel economy was nearly double that seen in standard vehicles. Fuel efficiency dropped 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.
Tips for Stop-Start Traffic
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."
Other Ways to Keep Your Car Cool
Other ways to keep your car cooler without relying on air conditioning include seeking out shaded spots or parking in a garage. Tinted windows and heat deflectors may also prove beneficial for drivers. Window tinting on vehicles can effectively reduce heat generated by direct sunlight by as much as 70 per cent inside a car. Since the vehicle stays cooler, drivers might be less tempted to switch on the air conditioning.
