Fords procedure states a "careful acceleration to WOT" or something like that. Many people got frustrated with the vagueness of it, so an internet standard was sort of adopted. The standard is now a steady 55-65 mph on level ground. Of course it requires the engine to be fully warmed up.
That said, if an oil cooler is 100% healthy, you shouldn't exceed the 15 degree differential even when towing. Some people worry about a 20 degree differential when towing heavy on a 100*F day. I wouldn't be too concerned with that, but 20*F would be my upper limit when towing heavy (as long as you were below the 15*F under normal driving).
Spoke to a friend and he said once the radiator gets rusts there's no taking it out. So just to use it till it breaks and then replace it. What would be the negative effects if I used just distilled water and wetter in the degas redivior until I have to replace the radiator then I replace it with the cat elc1? I plan on doing it in the next two weeks. And not putting more than 500 miles on the truck. Also I noticed while I stay still the eot and ect get close like 3 degrees apart to each other (178 coolant 181 oil) the coolant gets hotter and the oil gets cooler while I'm driving they're a constant 10-13 difference the coolant gets cooler while driving and the oil gets hotter(172 coolant 185 oil).... is that normal?
I was driving the truck and out of no where both the EOT and ECT dropped by 25 degrees or so. Then I also noticed that when I came to a stop and then accelerated it sounded like an 18 wheeler acceleration/ or maybe a vacuum sound (that loud hum and the harder I accelerated the louder it was)? After it dropped the oil temp wouldnt go above 150 and the coolant was around 135-150 also im pretty sure MPG dropped as well. there were points where the deltas were 17 degrees and it stayed there for a while. I parked it and letting it cool down to see if the same issues will be replicated. Any ideas on what it could be? I googled it and it could be the turbo is leaking somewhere so I should check the hoses. but would the turbo cause the decrease in temps?