My understand of it is, it senses when you are going sideways and corrects the diff accordingly so you always have just the right amount of grip, I love the evo x for its ayc, it makes it so easy to drive its basically just point and go.
Like the game says the higher the setting the faster you take a corner nad maintain grip. Also i use 80% on my evos and the grip it provides in corners is amazing play with it.
