Air Con - Leave it on permanently?

[peteo]

Any views on this? Honest John recommends that, ideally, with a manual system, the air con should be left on permanently. He describes the failures that can happen if the refridgerant and lubricant doesn't circulate regularly. He also recommends giving it a blast on full cold occasionally even during the winter.

My Golf Mk5 has the semi automatic air con, you actually have to turn it off using the "econ" button.

I get occasional probs with condensation in my car and wonder if I might be better off leaving the air con on all the time.

Anybody know if this will make a dramatic difference to my MPG? Any other views? Is HJ right on this?

[WeegieBob]

Air con permanently on will have an effect your fuel consumption, but as to how much I don't know, some say it can knock off as much as a couple of miles per gallon, so there's a cost penalty either way.

I was advised many years ago that air con should be run at least once a month for about five miles or so just to keep it good working condition. Yet on the other hand an American mechanic friend of mine advocates switching the air con off a couple of miles from home / work so that the condenser radiator doesn't sit wet when parked as the dampness corrodes the matrix (you often see pools of water under parked cars that are a result of the condensation dripping off the matrix), but how true this is again I don't know.

Certainly its a great tool if you have a car the mists up in the rain - my other half has a Micra which mists up in a heartbeat in the rain, so its rarely off up here in "sunny" Scotland.

WeegieBob. ;)

[Eshrules]

I have my Climate set to auto at around 18.5/19.0 degrees constantly, it keeps my windows clear and doesn't seem to affect my fuel consumption that much (possibly 1 or 2 mpg).

It is correct that when left for extended periods, issues are often found with the air con.

The man to comment more accurately on this would be Crasher, as I'm sure he's seen more than one failed/issue-ridden air con system in his time.

[zollaf]

thing with air con is it keeps you cold in the car. i was driving around all day years ago on a stinking hot day with the aircon on max. when i got out i almost fainted with the heat, so had to sit in the car with the aircon off for about 20 minutes to warm up a bit. so now i turn the aircon off before i stop.

[paul b]

I run with it on permanently. Doesn't seem to make a noticeable difference in real world driving, plus it stops the windows from misting up.

[kite]

I run my climate on "auto" all the time,surely the clutch on the compressor will cut in and out as req.
The aircon will blow hot or cold depending on temp. selected.

[peteo]

Thanks for the views and advice. I think I may leave it on most of the time now especially given that my car isn't used daily - all the more reason to keep things circulating. Up until now, I had used it, during the winter, for about 15 mins a month but I tend to think that might not be enough.

I'm never quite sure about the difference between VWs semi automatic system and full on Climate Control. On mine, you can set the temperature and the fan speed but it doesn't seem that much different from a normal manual system. I assume that the air con is on all the time on mine whereas with Climate, it will cut in and out.

[Issac Hunt]

I always run mine in 'auto' mode. Its nice in winter as it keeps the windows clean. There are lots of posts from people who have air-con issues - I think many of these never switch it on over the winter months, and then as we move into summer they turn it on and it fails.

I must've driven 200k+ in VAG cars and have never had a single A/C problem (plenty of other issues though!)

[mr scoops]

I always have the climate on in the Polo and the Golf. Don't seem to notice a marked difference in the MPG and it makes a more comfortable drive.