I have a 2005 F150; 5.4 engine; 4X4; 355 limited slip rear end; with an auto trans. I periodically tow a car on an open trailer; estimated combined weight just over 3,500/lbs. I'm in the midwest so the terrain is fairly flat. What is the general thought on turning off or leaving on the trans OD. Thanks.

 

frequency of shifting. the more it shifts the harder it is on the trans. If it gets into od and mostly stays there let it be if every slight grade change it downshifts, turn OD off.

 

The only time I use mine while towing is when I start up a hill in 4th gear and when I'm going down hill so it slows me down and saves my brakes.

 

I actually use mine when I want to make a pass. It gets the r's up and then usually does not double downshift. makes for a cleaner pass.. I ususallyleave mine in OD unless it is shifting a lot.