I'm gettin rid of my 2000 F250 7.3L (unfortunately) and have a new F450 King Ranch on order.
My 7.3L just runs and runs with narry a problem, and I rarely add anything to the fuel.
Now, with the ultra low surphur diesel, and this high fallutin 6.4L engine, I'm thinkin it just might be cheap insurance to add something at every fillup.
Part of the time I'll be towing a 5th wheel that'll be up near 20,000#, and part of the time I'll be gettin my gas at God-knows-where (that is if I can make it between places in those western states where the next diesel stop might be a couple a hundret miles down the road.
Thanks for your expert advice. (If'n your not from around here you sure as heck must be xspirts.)