Originally posted by: thomsbrain
the fan will blow "harder" because there is no pressure it has to work against, since it's taking out what it's putting in. try rolling down your window, you'll get the same effect (but without the extra fan noise caused by the intake). there's no difference in fan speed. it will blow "colder" because it's taking air it has already cooled and cooling it again.
japanese cars can do the same thing with any heat/vent output/AC combination. those pitiful Ford HVAC controls never seem give you all the options.
edit: "MAX" A/C actually puts less strain on the engine and improves gas mileage because the A/C doesn't need to be cycled on as much to cool the cabin. Honda mentions this in their manuals.