What is the best dually truck for highway driving?
1986-1996
With a manual transmission and 4wd

 

IDI NA is a bit slow to go
IDI turbo works well but not a powerstroke
PS has more pep but more electronics involved, hard to ruin engine from low oil as it shuts down once it sucks some air in
Gearing on some are very low making for high engine RPMs

 

I cant speak for the 7.3 but I had a F250 4x4 with the 6.9. The 6.9 is a no go even if you found a barn find with 0 miles, just to slow. Far as a Cummins/Dodge goes, after 2, 93's, one a 4x4 dually, and a 95 4x4 I'm not sure Id even buy a dodge product again. Ive got 2 buddies with 2017 Ram 6.7's. Both have the notorious 6.7 oil leak. A $5000 fix, seriously?? Far as the 5.9's went, the dually developed a bad knock, wrist pin or rod bearing?? at 167K so it went bye bye. The 93 2wd had all kind of issues on the truck itself. The engine ate the injector pump around 175K IIRC. The 95 4x4 had no engine issues, but had trans issues with 5th gear falling off the shaft, front diff and steering issues, and the bed self destructed. I loved that truck I'll admit even with all their issues. Far as power and MPG, 20mpg give or take. I can honestly say after 45+ years of trucks, the gassers were way cheaper to operate even at 10 mpg. If you need mass pulling power though, then go diesel. Even my current V10 Triton is no match.