I have noticed many times that when people mention the fabia air con... they mention that it is always running and not on a separate clutch system.

Turning on the AC mearly opens a valve to let air through...

Sooooo... what i'm leading to is:

If AC is on... is there any difference in fuel consumption as to when its off as its supposed to be "always running":confused:

Sorry if this sounds stupid, just i try not to use AC thinking of fuel yet with the cooler weather im always steaming up without it.

Dont know your answer but can't say I notice any difference with mpg with it on or off. Most of the time mine is on unless I want the window open. Be intersting to see what the answer is.

I notice a decrease in fuel economy with it on and I've always wanted to know this but never bothered to ask the question... awaiting with interest.

Glad someone asked the question as I've always wondered but thought everyone knew and I would therefore look daft. I too wait with interest

Hmm, my theory is that it is always at say, 2%, even when switched off. The more you ask of it (REALLY cold etc) then the higher the load, so more fuel used. However, even on the highest demand I wouldn't expect there to be more than 1mpg difference...

Just my tuppence worth.

If AC is on... is there any difference in fuel consumption as to when its off as its supposed to be "always running":

In my 1.4/16v, I notice quite clearly going uphill in a high gear that switching on the A/C reduces pulling power, and switching it off increases it again. So the A/C does apply an extra load to the engine and therefore must decrease MPG.

Sal

When I checked with Vag-Com, the actual fuel quantity injected at idle was 0.4 mg/stroke with the aircon off, and 0.6 mg/stroke with it on. I think the extra fuel is used to maintain the idle RPM.

Exactly Sal, it is allways on, but the loading does change.

What changes the temp inside the car is a small motor on the temp flap on the heater box which alters the mixture of hot and cold into the car. The Climatic ECU monitor the in car temp through a small sensor and moves the flap backwards and forwards to try and keep it as stable as it can.

Glad it wasn't just me wondering then... always takes a stupid question to get the answer!!

Thanks for the replys, more AC just not to drastic temp changes bye bye steamy windows!