a/c driving techniques

[hill]

When it gets into the 90's and beyond, not only are YOU more uncomfortable, battery temp management becomes more & more of an issue. DON't think your MPG's will stay high, if you run no AC at 100 degrees, because your battery efficiency goes down if you let 'em run that hot. And if it's 90 outside, your car will be maybe 10 degrees hotter with the windows up ... even if you're running the fan full blast ... because our black dash soaks up heat like a microwave. That means you're simply pumping hot air back through the battery cooling system.
So it's a trade off. You need cool, for battery management on hot days, but AC WILL drop your MPG's. To split the baby, what I like to do is cycle the AC manually ... maybe let the compressor run for 30 seconds, then switch back to vent only, for a minute or so. That way, the batteries are obtaining their dose of 'cool' (me too), but you save a bit on the MPG's. One last observation, our Prius MPG's seem to be the least affected by AC if we're driving a nice constant speed (whether 50 or 60 or whatever) fwiw.

[Fred_H]

And turn off the AC compressor a few minutes before you arrive.