MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: TaylorGTi on June 27, 2014, 07:54:09 pm

Title: Air con and fuel usage
Post by: TaylorGTi on June 27, 2014, 07:54:09 pm
Does anyone get less mpg using aircon?

It never made a difference in my past car (123d coupe) and was curious as my air cons broke so can't find out for my self  :signLOL:
Title: Re: Air con and fuel usage
Post by: bacillus on June 27, 2014, 07:56:17 pm
I usually see a 1-2mpg difference...
Title: Re: Air con and fuel usage
Post by: homesqueeze on June 27, 2014, 08:55:28 pm
I usually see a 1-2mpg difference...

Same here, the difference is negligible.
Title: Re: Air con and fuel usage
Post by: h45gti on June 27, 2014, 09:08:16 pm
once I get mine fixed ill know  :signLOL: trying to fix it my self first before I take it to a garage to resolve, bought a pressure switch, getting the correct spanner tomorrow, hmm diesel and aircon and then petrol and aircon,.. shouldn't be much of a difference? aircon in a diesel probably use less fuel?

EDIT: less fuel to run the aircon
Title: Re: Air con and fuel usage
Post by: OSB on June 28, 2014, 08:48:11 am
It used to be a 'rule of thumb' that aircons made fuel consumption worse by around 10%.
As improved compressor designs  have made them more efficient, it's probably more like 5% these days.
Anything that the engine has to drive, whether it's a aircon compressor, an alternator, power steering pump (ok I know we haven't got those!) etc., will add a load and increase fuel consumption by a small amount.
Title: Re: Air con and fuel usage
Post by: J400uk on June 28, 2014, 09:19:10 am
Only slight but it's definitely noticeable especially on a hot day when the system is working hard
Title: Re: Air con and fuel usage
Post by: cobz on June 28, 2014, 10:12:53 am
This is something I have tried to test myself... not the best conditions but I have definitely noticed 1 or 2 mpg less with it running. I just prefer to leave the window open.. can hear my car better that way  :wink: