[ken_railey]

As I mentioned, this was added in an edit - but even the A/C doesn't affect range as much as you might think. It is roughly ~8% in your typical ICE, which is less than rolling your windows down at highway speeds. No idea what the effect of running AC on a Tesla's range is though.

www.sae.org/events/aars/presentations/2004-hill.pdf

[jessaustin]

When I first heard the A/C vs. windows-down comparison it struck me as non-intuitive. I eventually reasoned that having windows down at speed results in moving much more air through the cabin than the A/C does. It takes work to move air, but it also takes work to run the compressor. There would have to be a break-even point at which having e.g. the driver's window and the rear passenger's window down a couple of inches each is cheaper than the A/C.

Interestingly, the graphs on pages 14 and 15 of the linked report don't appear to support your point. That is, the green curve is strictly less than the blue curve at all investigated speeds.