Just switched off my air con - what a difference!

[TVR Man]

Just switched off the air con on my 2004 S320 CDi (always used to leave it on permanently). Backwards and forwards to work (10 miles each way mixed dual c/way and town centre) gone up from just 30 ish mpg to 33-37 and distance (m/way) from 38 to 42-45 mpg. OK I drive it like a limo (I have the TVR for when I want to pretend I'm still a boy racer) - but that's pretty impressive for such a big motor and a 3.2 litre V6 auto I think.

Anyone getting more?

Dave

 

[psmart]

Sssshhhhh! Dont mention the aircon word!!! I tried to put this point across last year, that aircon (and auto boxes) eat fuel, but I was beaten back with a big brush!!

The official line is Aircon is godly and it costs nothing in fuel or performance

The official line is Autoboxes are godly and costs nothin in fuel or performance

Stick to the official lines and everybody will be happy

 

[Alex M Grieve]

Sssshhhhh! Dont mention the aircon word!!! I tried to put this point across last year, that aircon (and auto boxes) eat fuel, but I was beaten back with a big brush!!

The official line is Aircon is godly and it costs nothing in fuel or performance

The official line is Autoboxes are godly and costs nothin in fuel or performance

Stick to the official lines and everybody will be happy

Simple arithmetic and the fact that each of these devices consumes energy mean that you have to be correct. However, like others I have tried significant mileages with and without air conditioning, and comparing "sport" v "economy" settings on the switchable automatic gearbox and not detected any difference in fuel economy. In larger engined cars, the energy required to run the A/C should be but a small proportion of the total, so the gains cited here are impressive.
I have an S 320CDI of similar age and get over 40 mpg on long distances even if I press on a bit - probably 43 if I keep the rev counter just under 2,000 (but well up the torque curve). I find that driving style is probably the most influential factor.
Ever looked at instantaneous fuel consumption when you set off on a cold and frosty morning?!! Console yourelf with the thought that the 850 cc mini on choke was even worse (and not quite so quick).

 

[rf065]

Just switched off the air con on my 2004 S320 CDi (always used to leave it on permanently). Backwards and forwards to work (10 miles each way mixed dual c/way and town centre) gone up from just 30 ish mpg to 33-37 and distance (m/way) from 38 to 42-45 mpg. OK I drive it like a limo (I have the TVR for when I want to pretend I'm still a boy racer) - but that's pretty impressive for such a big motor and a 3.2 litre V6 auto I think.

Anyone getting more?

Dave

I think you must be sweating so much in this heat that you are driving slower and getting more MPG as a result. Switch the air con back on and chill. :wink:

Russ

 

[jubhi]

I think you must be sweating so much in this heat that you are driving slower and getting more MPG as a result. Switch the air con back on and chill. :wink:

Russ

lol

I didn't notice any difference either when I tried this experiment. However I just use A/C when I need to (like now!!) and never have it on all the time.

 

[Splatt]

Probably because the S class has got an A/C compressor the size to run a supermarket coldstore. Makes bog all difference to my little A class.

 

[Alex M Grieve]

Probably because the S class has got an A/C compressor the size to run a supermarket coldstore. Makes bog all difference to my little A class.

We have come a long way since the small cars (Micra, various Daewoos) which I have rented on Mediterranean Holidays, in which you could either use A/C, or overtake, or go up a hill - but only one of these at any one time!

 

[Rory]

distance (m/way) from 38 to 42-45 mpg.

That seems a big difference, unless you have it set to min temp. On long motorway runs, which is pretty well all I use it for, a/c on or off in my C270CDi doesn't appear to make any difference. It'll display around 50MPG, varying only if the traffic is busy or not. The compressor is cycling anyway, it isn't on all the time.


My daughter has 1.1L 3cyl Mitsubishi Colt, with amazingly effective a/c and you can feel it sapping power. Yet around town the display repeatedly shows 50MPG with a/c off and 48MPG with it on, so even in that it makes hardly any difference.

 

[100%Bitch]

Just put your roof down instead.

Oh silly me, I forgot, you can't can you?

 

[DMT60]

see helen,there's the snob again.LOL

 

[st4]

I tried driving back from Glasgow to home yesterday with the windows fully down instead of running my climate control with a/c preset to 17c (just the way I like it) as it was a scortcher of a day...

With climate on and windows up I get 40mpg.

With no climate and windows down I got 43mpg.

On both runs I had a similar driving style, making swift, legal and safe progress and the traffic was light on both runs as it was midday (joys of a job interviews at the moment)

Maybe because the A/C in my car has to run much harder to keep the sizable cabin space cool (its a black car so aborbs more heat) and also it will be running hard due to the cool temp I need (most go for 22c not 17c) so extra fuel is being used.

Not so long ago I had a BMW and therefore got the BMW mag every month. For a 3 series running a/c with climate on @ 22c a 1% dip in MPG was noted, with windows down and sun roof open due to increased drag a 6% dip in MPG was noted, ergo drive with a/c on, not with windows down.

This effect will worsen with a drop top, but if you've gone for a 55, I doubt that will matter too much

 

[100%Bitch]

see helen,there's the snob again.LOL

:lol::lol: You're learning. :lol::lol:

 

[TVR Man]

But you see Helen, I CAN put the roof down!!!

 

[100%Bitch]

But you see Helen, I CAN put the roof down!!!

Yes, but we were talking about your everyday car. Get yourself an SL. :wink:

 

[psmart]

Mmmm! Have you not considered that cold air is dense and heavy, warm air is light. Thus with the aircon on, your car becomes heavier and less mpg, with the sun scorching and no aircon, your car is lighter and better mpg.....

....or am I just grasping at straws

 

[JEZ.S320L]

Mmmm! Have you not considered that cold air is dense and heavy, warm air is light. Thus with the aircon on, your car becomes heavier and less mpg, with the sun scorching and no aircon, your car is lighter and better mpg.....

....or am I just grasping at straws

Have you thought about having a poo before you set off? Less weight for the car to carry = better mpg AND you can leave the aircon ON with no mpg penalty

We REALLY ARE grasping at straws, aren't we..??????

 

[SLinKyjoe]

and shave your head too. Hair would weigh a few grams and as Tesco say, every little helps.

 

[jon_harley]

I was going to contribute to this thread to point out that if I switch my aircon off, the emergency chocolate stash in my centre armrest will get all melty... but someone is probably going to suggest going without chocolate to save the weight!

 

[JEZ.S320L]

I was going to contribute to this thread to point out that if I switch my aircon off, the emergency chocolate stash in my centre armrest will get all melty... but someone is probably going to suggest going without chocolate to save the weight!

I've got it..!!!

DON'T switch your aircon on.

DONT start your engine

DONT use the car

Result? A MUCH reduced fuel bill.

 

[SLinKyjoe]

but someone is probably going to suggest going without chocolate to save the weight!

Don't be so stupid. How can one live without chocolate. Its the food of life.

Some people