Ok, question for you tribologist out there. I use Cenpeco S3 30 Wt in my boat's diesel engine and I have had very good service with it according to Blackstone. Low wear metals and high TBN retention strong Calcium and Zinc content, but it is the only UAO's I have seen with Barium of any amount in it (usually in 80's). It is my understandings Barium is used as a detergent. Any other use and why do you suppose they seem to be the only one using it?