上邊發錯， sorry

I just have one 4X4 Pathfinder with the same setup as you mentioned.  By reading the owner's manual, I learned 2H has no speed limit while 4H can only get you up to 55mph and 4L can only drive up to 25 mph or you will damage your transfer case.  In general, on dry or wet pavement, you need 2H for normal driving; slippery road demands 4H for sure but not exceeding 55mph and 4L is for off roading or when you try to wiggle out of snow or mud or trying to tow other cars out of ditch, etc.....Different vehcles may have different specific requirement, but on my 4X4 setup, using which gear is only limited by intended speed.