Rear aircon tip?

[missfixit70]

From the top tips section on the main site

I couldn't understand why my fuel consumption had gone through the roof." writes Charlie Ekin. "Instead of getting 600km to the tank I was now getting 400. Had the diesel pump and atomisers checked out to no avail. After about 15 fill ups, ie about £350 down the pan, I discovered the cause. One of my children had left the air conditioning unit in the back turned on! I was not aware of any cold air flow coming forward towards my driving position and I had no indication on the dash board of any air conditioning being on. In fact I'm such a skinflint that I always have the air con off on the main control panel. Even when the front demister is on, I still turn off the air con off. Thought this may be of interest."

Am I the only one that thinks the rear heater let alone the ac cannot be switched on from the rear if its off at the front (there is only one compressor for both) & even if it were left on somehow, 200km (drop in efficiency of @33%) per tank difference?????

[helen&tony]

Hi
Kirsty...you're not the only one thinking that way...switch at front performs the magic feat of switching the rear off
Cheers
Helen

[bub devlin]

I would concur. Though i rarely feel the benefit of air conditioning.

[francophile1947]

Definitely switches off at the front, although I've never tried it with the "rear" switch on and the front aircon off
The most it will make is a 10% difference to the fuel consumption and probably nearer 5% - I think you must have another problem, if your consumption has dropped like that

[missfixit70]

When we did our Italian run, I had the ac on most of the time & averaged just over 30mpg & that included climbing mountains & fully loaded with back box, best was about 35mpg & that was with ac on. So if the ac did actually reduce consumption by a third, that would mean it'd be capable of @52mpg, now that would be impressive

I'm wondering if this result was arrived at by the use of a dodgy fuel gauge rather than brimming & logging mileage? Still not sure how the rear ac could be on without being switched on at the front though?

[Alacrity]

I agree, rear heater & a/c will only work if it is switched on at the front. The rear controls will function if the 'rear' button is on but you will still not get a/c until the a/c is switched on at the front as well. Can't see how it would make that much difference to the fuel consumption anyway, I agree with Kirsty.

[Ron Miel]

I agree. I get much the same consumption winter and summer, give or take 1 or 2 mpg. In winter, I run the aircon, front and rear, only long enough to help de-misting/de-humidifying. In summer, I have it on probably 70% of the time up front (ask Mrs M, who can be seen wrapped in tartan blanket when pedestrians are in shirt sleeves or crop tops), and still run it periodically in the back - plus summer tends to involve more cruising at speed.