Air conditioning

[MORELLO]

How is it that air con' affects petrol consumption? What process is happening that causes a greater useage, and is it further affected when turned up? (not 'up' as in climate control, but as in number 4 on the fan)

[Catso]

In just the same way you have to provide power, in the form of electicity, to make your fridge work, you have to provide it in the form of fuel to make your aircon work. It takes energy to 'move' the heat from in your car to outside it.

Yes, turn it up, and you'll use even more fuel.

[Loosehead]

When the air con is on the engine drives a compressor, that's extra load = more fuel. Interestingly if you open the windows instead you create drag which means the engine is having to work harder so It's prbably comparable to have the air con on anyway.