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aal234

effect of air con on mpg?

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Does anyone have any idea how much of an effect running air con has on your mpg? Being tight I like to get as much out of my 306 turbo diesel as possible!

So for example how much extra fuel does it take to keep the in car temperature at 5 degrees less than outside? I know this will vary from car to car but any general ideas would be helpful.

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My mate with a Vectra loses about 4mpg with air con. I lose about 3 mpg so I turn the damn thing off (tight arse you see). 169144-ok.gif

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My car (Golf 130PD Tdi) has better efficiency in the summer (Approx +10mpg) and that s with the air-con working hard to keep the temp inside the car down.

I suppose this is what comes from having a black car with black interior though sekret.gif

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I've never noticed any difference when having the aircon on so i leave it switched on all of the time now. Was the same with all of my Audis, the S3 too. Only cars that I've noticed a big difference in is the Zafira and the Yaris.

Not sure why.

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[ QUOTE ]

I've never noticed any difference when having the aircon on so i leave it switched on all of the time now. Was the same with all of my Audis, the S3 too. Only cars that I've noticed a big difference in is the Zafira and the Yaris.

Not sure why.

[/ QUOTE ]

EEK2.GIFEEK2.GIFEEK2.GIF

How is this possible! Surely it must drop a little bit?

I thought that the air-con uses a fair bit of power when it is engaged? I read somewhere that it can be as much as 25% of the overall power as the air-con clutch engages.

Which surely in-turn would mean that in order to maintain the same mpg with it switched on, you'd need to compensate for the that 25% by using 25% less power (or being 25% more careful)?

Am i making any sense here? confused.gif

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Yes you are and it does in general. I am not sure how much by though but at least on mine it drops by 4-5 mpg.

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[ QUOTE ]

My car (Golf 130PD Tdi) has better efficiency in the summer (Approx +10mpg) and that s with the air-con working hard to keep the temp inside the car down.

I suppose this is what comes from having a black car with black interior though sekret.gif

[/ QUOTE ]

Noticed that too with my PD115, i get average of 48mpg running to work in summer with aircon(climatronic auto mode) on all the time, but now its down to 43-44!! weird!!

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depends on how hard the system has to work (ie difference between insode and outside temps, but expect to lose about 5% on mpg.

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i reckon the engine torque must have an impact too. All of the cars that i've never seen MPG affected were cars with plenty of torque (TDI's and S3) whereas the Yaris struggled.

With all of my Audi's, I simply leave the AC on all of the time, even in the winter. Dont ask why/how, i've not got a clue!

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Cooler air temp this morning and my mpg dropped off even though the aircon not working as hard?

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Well now I've gone from under 24mpg to over 40mpg, I don't give two hoots about how much aircon affects the mpg.

If it's hot or steamed up, I put it on.

If it's not, I don't.

I do however drive around with the lights off and PNV goggles at night to save a few joules, and I have disconnected any wasteful electric items such as power steering and ABS to make sure I get that extra 0.000001mpg.

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The car actually uses alot more fuel with a window open than with aircon on.

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[ QUOTE ]

The car actually uses alot more fuel with a window open than with aircon on.

[/ QUOTE ]

Only above 55-60MPH

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You all must have Scottish blood, what with your penny pinching, tight fisted ways!!

smile.gif169144-ok.gif

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Guys!!!

Don't we get enough MPG as it is, to be worrying about Air con running costs?!

grin.gif

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Thats dangerous mate smashfreakB.gif because your servo assisted braking will stop, and your powersteering stops also smashfreakB.gif

Better just either leave it in a high gear with the clutch up (no fuel consumed, but you get engine braking), or otherwise just put your clutch in (fuel is used to keep engine ticking over, but no engine braking).

PS surprised you didn't consider taking the spare seats out and only filling up £5 at a time to save on weight smashfreakB.giflol.gif169144-ok.gif

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I'm going to fill mine with helium, wrap it in cling film and use slicks to save on drag.

Who needs to breathe when you have 50mpg?

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[ QUOTE ]

I'm going to fill mine with helium, wrap it in cling film and use slicks to save on drag.

Who needs to breathe when you have 50mpg?

[/ QUOTE ]

and also only drive in the direction that the wind is blowing ices_blah.gif

Yeah, the coats already on....... slap.gif

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I have modified my engine so it only runs on 1 cylinder therefore I only use 1/4 of the fuel!!

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