WTF does Max A/C do?

[Homeslice]

Originally Posted by goof2

My guess, and it may be what Particle man meant as well, is when the A/C is set to get fresh air it is putting new air in the car. The old air has to be forced out somewhere creating higher pressure in the cabin. The fan runs slower because it has to overcome that pressure differential to get the new air in the cabin. When set on recirc it is drawing air from the cabin, cooling it, then replacing it back in the cabin. The fan does not have to work against the increased cabin pressure, its job is easier, and as a result it can run faster. I know in my truck when the A/C is set to get outside air its output increases if I crack the window open.

Hmm, makes sense. All cars have a cabin air exhuast, usually somewhere near the rear fender, but it's covered by a rubber flap so some amount of force is necessary to push air through it.

So then if all Max does is make the air recirc, then why do so many cars have both a Max button AND a recirc button? Do they think people are too stupid to understand what recirc will accomplish?