AC or open windows for MPG

Ok yeah...an old thread. No one has mentioned the heat, and required AC from the driver. The hotter it is, and the more demand from the driver....the compressor will kick on more often which uses more fuel.

In the Mythbusters episode, does anyone know the outside ambient temperature? They are usually in the bay area near SF where it doesn't get super hot. If thats the case, the compressor wouldn't turn on much. As for the aerodynamics of windows up vs. down....tempurature is negilable vs. mileage.