Tom, IIRC there have been threads in which others have recommended an
oil with a high ZDDP content....the name could have been Joe Gibbs or something like that. It sounds expensive but it does address those additive issues you mentioned.
Hope this has been some sort of help...try a search with ZDDP or Joe Gibbs...you might find just what you're looking for in an
oil formulated for gasoline engines.
Cheers!
Dugly
