I know this is getting to be an old question, but I hear so much conflicting info about it and my manual says nothing about it. I have a 2001 Powestroke F350. I towed the rig and trailer the other day for 30 mins on the highway with OD off, and I maintained 65mph at 2800 rpm! (Near red line.) It seems like overdrive was almost required. I'de like to be able to go faster than 65. But I've heard not to use it. I've also heard use it, but only on a flat surface. (Not up hills.) Additionally, I've heard use it so long as the tranny isn't jumping in and out of gears. So what's the real deal?
J. J.
J. J.