on dry pavement your transfer case would bind up and eventually break things, it is still a part time 4x4. AWD accounts for slippage in the transer case and more than likely a viscous coupling instead of a mechanical connection. Think of how a locker works as apposed to a LSD same concept as a part time 4x4 and an AWD, about the only time AWD could be better that 4x4 is on moderatly snowy roads if the driver isnt paying as much attention. That and no low range in the AWD.