Ken,
If you are interested you might want to contact DD and see what their tech people say about that particular oil. That might be something to share not only with POG, but the Prevost Stuff site.
I have learned not to trust an opinion from a tech or a dealer, (buses or planes). Sometimes we get fed old wive's tales, sometimes we get fiction disguised as fact and a lot of the time we get the truth. It is hard to sort out the fact from fiction so I try to do my own homework