How Much Gasoline Does Your Porsche AC Compressor Consume?

It is a no brainer that switching the on the A/C conditioning system in your car will have an impact on the gas mileage. That is because the A/C system works just like any other feature that draws power by consuming and burning fuel.  The big question however is does the A/C burn gasoline more than keeping the car windows down? If so, how much gas does it really burn?


Running a Porsche’s A/C system burns fuel as already hinted. However, the amount of consumption usually depends on the A/C compressor operation.  If you run the A/C on a hot, scorching summer day with the call full of passengers, then expect a 5% decrease in gas mileage or even more. A good example would be driving a Porsche with a say, 90HP engine that gets rid of around 9HP from the drivetrain when engaged. This will consume around ½ liter extra gas after 100km of continuous driving. What most Porsche owners do not know though is that Porsche A/C compressors consume the most amount of fuel when the car is idling but the engine is running.

The Effect Of Turning Windows Down

Your car’s A/C may or may not burn gas with the windows down. This depends on the model of your Porsche. It also depends on the speed of the car and your driving habits. The running of the A/C does not on its own burn gas. The open windows will however enhance your Porsche’s aerodynamic drag. This will force the engine to work extra hard and in the process, burn more fuel.

Driving on at 50mph with your windows open is therefore a little bit detrimental for your car’s fuel consumption. At such a speed, fuel efficiency drops. Fuel efficiency however increases with the A/C on. Do note though that this happens in old Porsche models. The latest ones feature automatic A/C systems complete with artificial intelligence capable of allowing you to make the necessary adjustments from your smartphone using an application.

When The A/C Burns More Gas

The A/C burns more fuel with open windows when one is driving at less than 50mph. This has already been explained, which begs the question, ‘what should one do?’ The answer is simple – keep the windows down when it is cooler outside. At that speed, the drag will be ignorable. The engine will end up consuming less fuel.

Driving On A Highway

The A/C suits better to a highway drive in cool weather conditions. However, if you find that the system drains fuel too much or it overheats the engine, turn it off. This mostly happens when the level of fuel inside the oil tank is extremely low. This tip is particularly helpful to old Porsche A/C compressors in old Porsche models.


Put your safety first before everything else. Saving some amount of fuel by turning the A/C off on a hot day can be detrimental. It can cause health problems or simply make it hard for you to concentrate on driving. Be sure to also have your A/C inspected from time to time to ensure it is always in a good, working condition.