Moved to a more appropriate forum.

I voted water to air because when you are at a stop light and the mustang next to you revs his engine and so do you the air that is coming in is going to be hot. So the water can still cool that some. But if its air-air then it's all gonna be hot and you will run sluggish until it gets colder air in there.

Good point. But I would think water to air would be tough to keep working.