Towing - Stay in RWD or change to 4WD?
We just purchased our first camper this past Monday and we are making our maiden voyage tomorrow. Our tow vehicle is a 2013 Expedition EL and it has an option for 2WD, 4WD Auto, 4WD High, or 4WD low....
Forum Discussion
Much of the information posted is only applicable to traditional 4WD systems. Ford's ControlTrac system allows the vehicle to operate in 2High or 4Auto on any roads. The transfer case DOES HAVE a computer controlled clutch (acts as a center differential) that allows for the necessary slippage in 4Auto. In 4Auto the front hubs and front driveshaft are engaged, and the torque split is around 10/90 front/rear. If the computer detects a difference in driveshaft speed it can engage the clutch sending more torque to the front as necessary. Anytime we get rain or I hook up the trailer I set to 4Auto. Our previous Explorer did not even have the 2High option, it was always in 4Auto. It is awesome for towing, I don't have to think about it. It is not quite as seamless and smooth as a true AWD like the Subaru I owned, but it is pretty good. Combined with AdvanceTrac and RSC it does a great job keeping the Expedition going where you want it to and tire side down. Wikipedia has a very good article about ControlTrac, its history, and how it works.
