You are right, boo! We did not answer your two basic questions! I do not know about the Rotella. I do know I have used Castrol Syntec full synthetic oil in all four of our scoots and it is "car" oil and have had no problems. The oil bottles do not say anything about anti-foaming.
Karl
Thanks Crossbolt.
This is the kind of feed back I am looking for.
" Have used car oils for years in four scoots without problems".