Pablo,
The same thing that happens with any other rotating or rubbing surface. If the hydrodynamic film breaks, the moly acts as a back-up AW/EP additive to prevent catastrophic failure.
Since the oil temps in the turbo are usually higher, I would think the moly would start forming an organometallic surface film long before any hydrodynamic film rupture.
[ November 26, 2002, 10:27 AM: Message edited by: MolaKule ]