probs only take of 2-3MPG at the most

Wat paul said, but i wouldnt say it drinks alot, you could probably notice it on a full tank. i know i havent used my air con in a month or two.

When the AC is running, its driven by an aux belt which is connected to the crank n stuff, so then puts more stress on the engine, so then the engine needs to inject a bit more fuel to let it idle properly, etc...

As for light holders, unsure m8

Hi,

Does any one know whether or not the osram bulb holders behind the dials in the corsa will fit behind the MK4 Astra dials?

And does anyone know how exactly A/C uses more petrol?
Like what is the basic mechanical process.