I can’t quickly find the mileage with the AC not running. More to the point, it is mostly a myth that running the AC uses a significant amount of fuel. The compressor is usually driven by the serpentine belt, and adding the clutch plate for the AC into that system does not add significant drag. A little, yes.
> it is mostly a myth that running the AC uses a significant amount of fuel
What?
Modern car AC compressors use about 1 HP (.7kW) of power, with a duty cycle highly dependent on temperature but if you break the seal periodically, like by opening the window to put mail in a box, it will be running 100% of the time even on an 80 degree day. For a hatchback at 70mph that's up to 10% of your energy usage. It's much harder to quantify for stop and go traffic because you have a bimodal situation of either zero HP generation or like 50 HP to accelerate in slow city traffic, but all ICE vehicles use more energy (have less economy) in city driving than highway driving, so on average it's using a higher percentage of your energy consumption in city driving.
So turning on the AC on a hot day will reduce your economy car's mileage from 33 to 30, your truck's mileage from 12 to 10.8, and your Prius from 48 to 44 and worse for city driving. The numbers they claim in the above studies suggest they are using a higher capacity compressor to deal with the air volume constantly being opened to the outside.
