Yeah there are some simple things that ford definatly paid attention too
first off is the 6 speed, deeper overal over drive, first overdrive isnt quiet as deap as say a 4r or 5r. You get a lower first gear so taking off is much easier fully loaded, all this allows you to run a 3.55 gear with a big tire no problem, even towing.
The biggest part is the actual transmission tuning it self
Torque converter locks as early as 25mph, it stays locked almost all the time, each shift it does unlock for a second and then relocks, sounds like a bad idea but it almost acts as a splitter between gears, its awesome. you never get that dodge or even 6.0-6.4 thing where you are making a bunch of rpm but not really accelerating, with a 6.7 all you do is pull, its amazing the on ramp speed you can get merging into heavy traffic fully loaded, i often pull gaps on cars getting on the highway with my camper.
they are also much better about downshifting and engine braking, almost to the point where if you arent towing more than 10k you really dont need the tow haul mode, its almost too much.
my truck has 12.5k miles on it and 4500 of that is with a trailer so far, love it every time i tow
Only two complaints is
rear is a little soft, so leveled you need to either run an air bag or timbren helper spring to the rear (timbrens have been working really well for me) if you are stock height its probably no issue
small fuel tank on the ccsb does suck, they claim its a 26 gallon tank but its really only about 21 gallons usable with the distance to empty on the dash, im going to do something about that eventually just havent figured it out.
Best truck i have ever owned, set the cruise and forget it, so freakin quiet even if it does down shift you wouldnt know unless you watch the tach, rides sooth, creature comforts are good, seats are upgraded from previous models, all and all i cant say much bad about the 6.7
DEF if you decide to leave it stock i have only added 2 times and that was 6000 miles each time, cost me 22 bucks both times.
