Does choosing open windows over the aircon save petrol?
The answer may surprise you!
John Maytham interviews Nicol Louw, Author at Car Magazine.
Listen below.
Summer is here, but so is Januworry. Cutting costs while trying to keep cool is important.
For some people, rolling down their car window - instead of turning on the aircon - is a hack to save petrol money, but how true is this? Does driving with the windows down significantly affect fuel efficiency?
Actually, it's the complete opposite, says Louw.
For most standard cars driving at 100km/h with the windows down, to overcome aerodynamic drag, between 20kW and 30kW of power from the engine is needed.
If you're using an aircon, only 1kW to 3kW of power from the engine is needed.
In short, Louw says that there is "no point" in ditching the aircon for the window to try to save on petrol.
"Opening a window on a vehicle is very bad for aerodynamics."
Nicol Louw, Author – Car Magazine
"Above 60km/h; no point in having the window open. Just go straight for aircon... you won't use any more fuel.
Nicol Louw, Author – Car Magazine
Scroll up to listen to the full interview.