Air con

[Stulc]

I know in another post it was suggested that just now I have the a/c on all the time to keep window's clear ect, but just how much more fuel will I use as Iv'e allsorts of horrors over the years that you can drop as much 5 mpg how true/false is this.

 

[SLinKyjoe]

that well renowned truth device, called TV, show a programme on discovery called Mythbusters.....they ran some big yank 4x4's round some track at about 45mph for 5 US gallons(about 19ltrs). 2 canyoneros went round, one with A/C on the other with A/C off and all the windows down.

The car with the windows down was 15% more fuel efficent than the one with windows up and A/C on.

bear in mind that these yank tanks were 12 yards long and 2 lanes wide, sixty five tonnes of american pride! so they weren't fuel efficent to begin with....it should stand to reason that normal cars will be less ineffecient.

i have not had any difference noticed with mine on or off. some have noticed up to around 2mpg differnece lower with A/C on. but in winter you will be using more as you will have your window heaters on, maybes the fan blowing harder, heated seats etc and lights on which all eat into your MPG.

and i would prefer to see where i am going by keeping my screen clean, than worry too much about the negligible fuel it uses.

still, someone may have a more accurate economy with and without to make it less of a worry for you.

 

[jberks]

Stu,
On an C280 it won't make much difference. It can be a problem for 1.1L cars as the 5hp they need to run is a large hit when you only have 65 in the first place. I'd expect to lose maybe 1mpg or so but little more. Also, the gas lubricates all the joints and seals, and keep the system sealed. Running with aircon off for any period of time is actually quite bad for the system. I rarely (read never) turn mine off. As a result, I don't have steamed up windows and I don't have gas leaks. I reckon 1mpg is a price worth paying.

 

[Stulc]

Thanks guy's.....no I didnt really I'm not turning it on because I dont want to use more fuel, and as Slinkyjoe said he would rather see where he was going and use a few extra quid in fuel than driving in a dangerous situation, and I aggree.

All I meant was like I said previous, I'd heard so many horror stories of some car loosing as much 5-8 mpg, but like you say in an engine such as the 2.8 V6 your not going to notice much diffirence really.

And another point......you dont buy a car like a 2.8 V6 for economy that much anyway, it was because it was an auto est that sold it to us....and of course....




It's a MB....