Ford's specs are designed for vehicles that are unmodified. The more stress you put on the engine/powertrain, the more revisions you should expect to those specs. 205F for the trans fluid may be nothing to worry about IF that consists of a few spikes here & there (such as going WOT, being stuck in slowmoving traffic occasionally, etc) and temps generally stay in the 180-190F range otherwise. Since there is no cooling of the PTU in most instances, the less the heat transfer from the trans, the better, an indirect benefit. Obviously Ford knows the benefits (they don't tell us all their secrets
), otherwise why would the PP exist? They have top-notch engineers. But what engineers can design and what they are allowed to design are hardly ever the same thing in a corporate context.
As far as coolant temps, ask Torrie why he recommends the 170F TStat for "hot" tunes, or LME why they recommend the even colder 160F TStat. Ask them what they see for normal cruising temps vs spikes.
We WANT the additive packages in the fluids to last as long as possible, no matter the interval we choose to R&R. The SAE specs used by mfr's seems like the USDA RDA for food. Minimum required to survive. But if you are an athlete, that RDA is nowhere near what you require to "survive". On top of that, you are going to pad your chances of survival by making sure your body is stocked as well as possible.
