My 05 6.0l had 150k on it and all I did was replace an EGR valve. All around solid motor if properly modded. Traded that for my current Ford 6.7l. To the OP, any diesel fuel additive that boosts cetane #'s and more importantly adds lubricity to the high pressure fuel pump, which is sadly missing in today's ULS diesel fuels, are good. I use PowerService grey bottle in summer, and white in the winter.
2012 Eagle 320 RLDS
2012 Ford F-250 Crew Cab FX4, 6.7l PSD
3.55 E-locker, Timbrens