Quote: Amazing the different experiences people have. Wonder how many problems are really lube related . I run Royal Purple full synthetic in my 408. Three years now. Change it once a year. No abnormal wear or scuffing problems that I have noticed - and I have had several bad over heats due to blown belts. I usually run one or two grades lighter in viscosity than if I were running petroleum based oil. Definitely believe there is a friction advantage with synthetics - without film loss. I do run a zinc additive with it as I am running a large flat tappet hyd.
I think that the last sentence to your post is the difference.
. I run Royal Purple full synthetic in my 408. Three years now. Change it once a year. No abnormal wear or scuffing problems that I have noticed - and I have had several bad over heats due to blown belts. I usually run one or two grades lighter in viscosity than if I were running petroleum based oil. Definitely believe there is a friction advantage with synthetics - without film loss. I do run a zinc additive with it as I am running a large flat tappet hyd. 
