AC OR NO AC

Hey there! We are back again to help. The issue of using AC or not causes a lot of debate everywhere. Some say it decreases the car fuel efficiency while others say it does not.

So the thing is this: the AC compressor gets its mechanical power from the car engine. In simple terms, the car engine gets more load and therefore consumes more fuel when the air conditioning unit is put on. On the other hand, the car experiences what is called aerodynamic drag if it is driven with the windows down, and this also makes the engine work harder to maintain a car at a particular speed, thereby reducing the fuel efficiency. So the question is which causes more harm?
The extra load the air conditioning unit adds to the engine is fixed, irrespective of the speed or driving conditions of the car whereas the drag experienced by a car increases with higher speeds. This has been confirmed by experiments and has been concluded that for speeds below 80km/hr, it is more fuel-efficient to drive with the AC off and the windows down while it is more fuel efficient to drive with the AC on and the windows up at speeds above 80km/hr. This is because the added load to the engine from the AC is more than the effect of drag on the engine for speeds below 80km/hr and vice versa.
A good way to make the AC more effective is to use the recirculation feature. This reduces the amount of new air intake from the surrounding and makes the air inside the car cool faster. It also prevents foul odours from the surrounding from getting into the car. Also, park in shades as much as possible.
The way to really maximise both engine power and fuel economy especially at high speeds is to drive with the AC off and the windows up. Of course this isn’t comfortable because of the heat and therefore can only be done in cold weather and preferably for short periods. Be sure to put the fan on and switch the air recirculation feature off so that fresh air can come in from the surrounding. All the best!