Engine oil

I went to the bio-oils site and they have no testing info on their products other than environmental, and claim that bio oils are a new thing. The car you see as me avatar was filled with Castrol-R a castor bean based racing oil. Recent tests put it at a par with todays synthetics.
That was back in '73.
Again Ill speak with dad and see if he will join the discussion, I warn you though he is a very technical guy.
Andrew