I am not sure about the manual locking hubs.

Its funny you tell me not to top off my tank. I am the master at doing this and in no way thought it could harm the vehicle. I always top it off till I can barley squeeze anything left into it. Well not all the time, but you get my drift. I will start doing that method though. I am waiting for my tank to go down but ever since I rebooted the computer I have been getting what looks to be like fair milage.