I have a 514ci and my engine builder recently suggested I change from Royal Purple
synthetic (had it since new) to Pennzoil Racing (natural..not sythetic). The reason? He thinks the non-roller cam 514's do better with natural
oil vs.
synthetic. Any thoughts? A 460 owner wrote me that when he went from synth to regular his motor started leaking (odd..usually happens the other way around!)...thoughts?
Josh