most 4 wheel drives are engaged with a lever or switch and then low or hi is selected with a lever or switch, where you have awd you dont have to do anything. if you need 4 wheel drive it does it auto. on the jeeps you have both, the grand Cherokee has all time 4 wheel drive, but you have to put it in hi or low by hand. on other jeeps you have to put it in 4 wheel drive by hand and hi or low by hand. most of the cars and vans that have awd dont have a low gear and you wouldnt know it was there unless you read it somewhere.