"Auto" Climate control affect mpg?
 

Hi chaps,

this is aimed at the classics.

Does anyone find aving the climate control on auto, and even having the AC button off, and it warming the car, massivly chunks the MPG?

My aircon needs regassing, but surley the auto without using the aircon shouldnt affec the mpg? Or does it engage the AC irrespective of whether its cooling or heater and whether the ac button is on or off.

??

Your auto button can operate the air con, It shouldn't have a massive effect on fuel consumption, then again if your system needs regassing it's quite possibly not working at all! It's got to be worth getting it checked , peoples misconseptions of aircon is very common. Heating and cooling has nothing to do with aircon. I'd say get it checked out have an aircon service not just a regas

you should only see a noticable loss when when the compressor clutch engages and this will only hapen when you have the air con button button pressed.
if you have the dial set to auto and the air con button off the compressor clutch will not engage.

Ok, you set your dial to auto, your temperature dial is set to say 25 deg, what this means is that it will try to maintain a temp of 25 deg in your cabin area, so yes it does operate the aircon/heater system to do so (hence why its called "Auto(matic)") :lol1: and climate control (not basic air con)

Tony:)

Ok thanks DJ.

If the Auto turns the AC on does the button light up? Simple question i know.

Yes my aircon does need a service, however im imagine its as DJ says and shouldnt engage if its heating. One hopes it can reduce heat by not using the heatermatrix rather than resporting to engaging the compressor.

So it shouldnt affect mpg.

Todays tests confirm that is the case also.

Cheers

It will engage no matter what if set on auto, its not air con its climate control. ie it maintains a steady temperature in the cabin (hot or cold), to stop it just move the dial off auto ;)

Tony:)

ill add to what tony has said.


you can leave the dial set to auto all the time. the compressor will only ever kick in if the air con button is pressed IN. so you can leave it on auto and leave the air con button off and the compressor will NEVER kick in.
by leaving the air con button off you are telling the system you dont want the compressor to kick in EVER.

in this state above if it were a hot day and you had the dial set to say 20 it would never reach 20 though because try as it might the system will never be able to cool the air enough because it needs the compressor for that and it has been turned off.

When the air con button is OUT compressor is off, when IN its on (and in this state it will kick in and cut out as it needs, you will hear it)

Just set it to AUTO and 25 deg and air con button OUT, and happy driving! mine never moves from this.
i only use the air con button in summer if its mega hot.

Here's another common misconception! Dj are you saying you only use your air con in the summer? The use of air conditioning is for all weather types, it's as useful in the summer for creating a comfortable cabin temp as it is in the winter for demisting your windows! Temperature has nothing to do with air con! It's all about removing moisture fron the cabin to create comfort. With your settings to auto and where ever your temp dial, providing the entire climate control system Inc aircon is in top notch shape it should run the a/c pump when set to auto. No matter whether the light on the button is on or not. You may find when you set the position to blow on the screen it sets the a/c on too. It may be an idea when you have your aircon service get the tech to show you the correct ways to use the system.

yes cos it only gets hot in the summer :-), i only use a/c when i need to cos it saps fuel, the point of the thread. - agree with what you say though.

no, the compressor will only kick in when the a/c button is pressed!!
go and try it!

is it normal when on auto to cause the blower motor to run at full power all the time?
Cheers,
James.

No, it adjusts the temperature in the cabin with climate control gently when its got it there, if you just jump into a hot car for instance then it will blow on full until its down to the temp you have set.

Tony:)