When running the AC, if I set the temp a bit higher, does it actually run the compressor less, or just mix some hot (or outside) air with it?
The AC compressor is electrically driven and variable speed. It may just slow down or shut off depending on the amount you raise the temperature. I always leave my climate control system in Auto A/C and adjust my comfort level with the temperature switch on the steering wheel.
The AC compressor runs as much as it needs to. It's electrically driven, so it can run while the engine is off. How it is managed is entirely different than in a standard car. It doesn't run for a short time, then stay off for a short time like a belt driven unit. It varies it's speed depending on demand. How exactly it behaves when set higher is something I don't know, but I doubt Toyota's engineers would have it running hard all the time with the actual output temperature controlled by mixing with outside air. That wouldn't be very energy efficient.
