"Michael R N Dolbear" wrote in news:01ca1c49$817ca3a0
$LocalHost@default:

Air conditioning is an interesting topic. It does use a small
additional amount of fuel, but in a car, that additional amount is
smaller than would be caused by the increased drag when the windows
are opened.

Even if that is true and relevant, the standard car figures have the
windows closed (as well as AirCon.excluded/ off).

I don't know the real answer either, but a car with aircon is carrying the
extra weight around all year, and there must also be a slight extra drag on
the engine all year as the belt to the aircon compressor is turning all the
time.

If the car stays in the UK, especially the more northern parts, I would
imagine that cost of that over 365 days is just as significant as the
additional fuel cost when the aircon is running for, say, 20 days in the
year.

Peter

--
Peter Campbell Smith ~ London ~ pjcs00 (a) gmail.com