Tricks to save fuel with air conditioning

With thermometers showing temperatures above 30 degrees. In addition to protecting your car from the sun and monitoring problems with the air conditioning, there are also tricks to ensure that the air conditioning cools properly without causing greater fuel consumption. And not only that, also for extend its useful life and that it can start to fail at the most inappropriate moment and end up with the cabin turned into an oven.

And the air conditioning affects the vehicle’s consumption. While on, a compressor It sucks the refrigerant gas and passes it to a condenser, where it returns to a liquid state in a radiator… to the expansion valve, where it passes back into gas and cools. After cooling the air, it passes thanks to a fan through the grilles of the dashboard vents… and start again.

This entire process of removing heat from the air through mechanical processes (sucking air from outside or recirculating air from the passenger compartment) wastes energy, which comes from the car engine, which must make more effort: In addition to moving the vehicle, the engine must operate the compressor. This extra effort translates into a Increase in consumption between 5 and 20% (a few tenths in consumption, although it varies depending on the type of car).

And yes, performance is lost, but you will only notice it in cars with small engines and demanding a lot from the air conditioning. It is also true that some modern vehicles choose to disconnect the air conditioning if the pedal is pressed to the floor, so as not to compromise safety by demanding maximum power.

Before entering

It is obvious that the more we try to lower the cabin temperature, the more energy (fuel in this case) will cost to achieve it. Therefore, using tricks to cool a car quickly can save some fuel.

When starting

Do you get to the car and discover that it is like an oven? To help the air conditioning work, the ideal is that during the first minutes of driving you proceed to open the window a little.

Yes, at the same time you turn on the air conditioning. Since hot air weighs less than cold air, it tends to go upward. This way you help it leave and be replaced by the cold more quickly. After a while, you can proceed to close them.


In our tips to use less fuel we already told you that lowering the car windows worsens the aerodynamics. That will make the car spend more… but that aerodynamic loss is not too great if the speed is low. According to several studies, the critical moment is 80-90 km/h (From there, the air that enters “brakes” the car. Hence, on slower urban trips you use less fuel with the windows down than by fully using the air conditioning to cool the car.

Sometimes, when the heat is very high, lowering the windows is not enough to guarantee a comfortable temperature… but opening them will renew the hot air of the car, lowering the cabin a few degrees and making the compressor work less… using less fuel.

Have you used it in winter?

Like any component of the car, that it comes into operation regularly is a guarantee that it works when needed. So do not hesitate to use it for actions such as defogging the windows in winter. In addition to gaining security (it is much faster to gain visibility), you ensure that it does not break down due to lack of use.

Don’t force it

To prevent the air conditioning from breaking down, it is also vital prevent it from working at maximum power. In this sense, remember the first two points to lower the temperature of the cabin before starting the journey… and once on the road, be rational with its use. You don’t have to freeze either. The ideal temperature inside the car should be around 22 degrees. Anything lower than that temperature is an unnecessary waste of fuel.

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