On that point I would have to call on a now former (sadly) colleague of mine, who earned and uses his PhD. in tribology, the science of materials moving relative to each other, friction, wear, and how to deal with it all. Yup, an entire discipline devoted to this. He could tell us so much about different wet and dry lubes, hydrodynamic lubrication, etc. I enjoyed our conversations and learned a great deal.
I was similarly skeptical of that very notion, but he enlightened me that a lube that minimizes wear often does not afford the easiest motion of the two parts. Maybe it is a function of a lube that better protects against wear also causes more drag, resulting in higher parasitic losses...I don't recall.
Most of his work was in the automotive field, and I recall seeing diagrams of gears and loading in rear ends, where the lube is balanced to handle wear, friction, impact/shock loading, cooling, and so on. I may have one of his PowerPoint presentations somewhere in my computer. I'll have to take a look for it.
