this past weekend me and my wife was coming home from our trip in kentucky, i was hauling camper with my f350 6.4 and she was pulling our 25ft pontoon with my f250 v-10, we was driving normal and we came into the hills in jelico tenn coming down 75, we was driving about 65mph nothing fast just normal we came upon a new dmax truck and new dodge cummins, they was pulling campers about the size of mine about 33ft, wehn we came to start pulling the hill they started fading pretty bad, my 350 hit 4th gear and pulled at 65 and my wife was behind me doing same with v-10, we started passing them and i heard them hit trucks wide open trying to keep up, but they was dust,and the bad part is we was just driving normal not trying to prove anything, some of these trucks like that when we travel seems like they have a hard time more than they should, i thought 800ft tq would not fade like that