Air Con & Fuel.....

[Ifti]

A [stingy] mate of mine told me that he didnt use air con very much since it used fuel?

Is this correct? If so, how much fuel can having your air con switched on possibly use??

[v2brett]

it will use a bit more, not sure on the exact figure but i can remember JC on topgear saying a civic will do 6mpg less if the aircons on        but i think the bigger the engine the less fuel it will use as its not struggling as much.   IMO its worth the fuel

[bacillus]

I recon it's about 2mpg difference on my car...

[vwrascal]

deffo worth the extra vpower wasteage today, I was cooler than zac efron holidaying in the antarctic 

[Ifti]

I really didnt think it used that much. I have had the air con on recently, and have been getting around 2-3mpg lower then usual, on a normal run. I actually thought somet was wrong initially, but forgot about having the air con switched on! lol

[JonnyG]

There was a post a while ago with someone complaining about low mpg

They were advised to try not using AC, heated seats etc 

I think there mpg went up by about +3mpg as a result   

[Ifti]

I thought heated seats and AC etc used battery power.
Why do they consume fuel as well?

[BeezerDiesel]

The aircon is a mechanical unit driven by a belt, this it makes drag on the engine. The aircon blower is electric as are the heated seats and rear window/mirrors etc. If these draw a charge constantly they will be draining the battery which in turn will need extra juice from the alternator. The alternator like the aircon compressor is also driven by the engine.
Combined, that's a wee bit of fuel usage that's not going to the wheels.

Unscientific answer I know but you get the drift.

[Ifti]

Yup I get it now, cheers 

[winrya]

But you also have to consider that the fuel consumption increases by 10% with the windows open   

[bennylenny88]

my mpg goes down straight away 

[neg]

I read somewhere its like carrying another passenger - not the end of the world on days like today but when its not needed I always put mine on ECON.

[Ifti]

But you also have to consider that the fuel consumption increases by 10% with the windows open   

I always put the air con on rather then drive with the windows down at a higher speed - the wind noise does my head in!
However, like the above, I usually have it on ECON and only use air con when its a really hot day, or when I have the kids in the car.

[Steve82]

But you also have to consider that the fuel consumption increases by 10% with the windows open   

I always put the air con on rather then drive with the windows down at a higher speed - the wind noise does my head in!
However, like the above, I usually have it on ECON and only use air con when its a really hot day, or when I have the kids in the car.

Same as myself, use it on Econ most of the time unless its a very hot day!

[Jules86]

Aircon is better for fuel consumption than leaving the windows open 

If anyone watches mythbusters they tested it thoroughly and aircon won