Peter Campbell Smith wrote

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.

Which reminds me that the energy usage figures for electric cars don't
include winter heating either. One of the advantages of internal
combustion is that heating is almost free whereas in Britain (and even
more so in Canada) an electric has to use resistance heating. Making
sure the battery doesn't freeze is also required.

--
Mike D