Ford never recommends transmissions be flushed. The interval to change the transmission fluid and filter is 150k.
Well, damnit. My dealership just told me that I needed to change the trans fluid at 70k as "standard maintenance". $250 charge.
And in regard to engine oil... I thought Mobil-1 5W30 was the specified oil for this truck. Full synthetic.
My concern for a turbo motor and conventional oil would be coking in the lines and turbo from heat soak. This builds up sludge over time and reducing cooling and lubrication. In high hp racing applications, I have always been fond of Rotella T in all its forms. Fantastic stuff formulated specifically to handle turbo heat soak.
Also... I had a friend whom bought into the while Amzoil thing. Had a head gasket leak... and low and behold. Engine coolant plus Amsoil equals solidified jello. Buh bye motor. Could not have been more surprising to see the oil pan pried off of that thing.