Does the aircon really waste fuel?
The recent fuel price projections has SA motorists looking for hacks to save on fuel, but is the aircon a good place to start?
While grappling with soaring fuel prices, South African motorists may be looking for ways to reduce their fuel consumption. What probably springs to mind first is turning off the fuel-guzzling air conditioning (AC). There is a commonly-held perception that having your windows down conserves more fuel than running the aircon.
However, some motoring experts argue that driving with the air conditioning ON is in fact more fuel-efficient than driving with the windows down (at least at speeds exceeding 80km/h).
The reasoning being, the latter creates a lot of wind resistance, resulting in higher fuel consumption.
As petrol prices increase, it’s good to know which option can save you money at the pump.
THE ARGUMENT FOR THE AIRCON
Cars encounter air resistance (also known as drag) when moving through the air at any speed. Nowadays the majority of modern vehicles are aerodynamically designed, which allows them to move through the air with minimal resistance.
Nonetheless, if a car has its windows down, air will pass into the car rather than flow over it. This causes the engine to work harder and use more fuel to move forward.
Research indicates that driving at approximately 80 kilometers per hour with the windows down can reduce fuel efficiency by more than 20%.
It was found that air conditioning also decreases fuel efficiency at that speed, but only by around 10 percent.
THE ARGUMENT FOR WINDOWS DOWN
Using air conditioning is seen as more fuel-efficient for higher speeds, but this depends on the effectiveness of a car’s aircon system.
Older car models may well chew through petrol just as fast as having the windows down.
A BALANCE OF BOTH
When travelling at speeds of around 60km/ per hour or less, having the windows down and the aircon off is actually considered a more fuel-efficient option.
To minimise fuel consumption and your environmental impact, using a combination of the windows down and air conditioning is recommended.
Considering the appropriate option ultimately comes down to one’s travelling speed.