What determines the duty cycle of the A/C compressor?

[BailOut]

Originally Posted by ka0sx

The only thing is that you are probably reducing maybe 1/2 mpg running the AC in a car like this so there shouldn't be an argument over something like this. I don't care how much of a tree loving into the green hype hippie someone is. 1/2 mpg is not going to change anything.

Actually, running the a/c is a 6-11% hit on MPG any time the compressor is cycling, which is much more often than not. That makes it exponentially less efficient than your initial thinking, and puts it well into the realm of measurably using more energy under "normal" operation, and measurably wasting energy if one has the windows down at the same time.