there's been an oil thread over on the strokers list. if you're trying to protect your older engine from cam wear and failure, what it comes down to is zinc and phosphorus levels; they've been reduced as they slowly poison catalysts, and modern roller tappet valvetrains don't need it anyway. [maybe cause and effect?] the article kyung linked to is especially enlightening; the old zinc phosphate levels were apparently set from research published in a 1977 sae paper it mentions. in short, what most of us want to look for is an API rating of SG, SH, SI, or if necessary CI. or add a can of GM EOS with every change. === . === All other ratings for the ZDDP package are defunct - no longer applicable other than CI-4. The new API CI-4 rating for the ZDDP package is only in Mobil 1 Truck & SUV / DELVAC or Shell Rotella T. BMW OIL - is relabled Mobil 1 DELVAC - and used in BMW cars - trucks - motorcycles. The only reason it will 'slowly poison' catacytics is if your engine is BURNING OIL. -- ___ =Bt= /~ ~\ milnersXcoupe |_ | "The Heretic" |/ __-__ \ /~ ~~-_ ~~ -~~\ ~\ / | \ , / / \ // _ _---~~~ //-_ \ / (/~~ ) _____/-__ ~-_ _-\ _________ / _-~\\0) ~~~~ ~~-_ \__--~~ `\ ___---~~~ /' /_-~ _-/' )~/ /' (___________/ _-~/' _-~~/ _-~ _ ----- _~-_\\\\ _-~ /' __--~ (_ ______---~~~--_ _-~ ~-_~\\\\ ( ( -_~ ~-_ | ~-_ /~~~~\ \ \~~ ~-_ ~-_ ~\ ~~--__-----_ \ ; / \ ______-----\ ~-__~-~~~~~~--_ ~~--_ \ . | | \((*)~~~~~~~~~~| __--~~ ~-_ ) | | | \ |~|~---------)__--~~ \_____________/ / , \ ~-----~ / /~ ) \ ~-----~ / ~-_ _-~ /_______________________________/ `-_ _-~ ~ ----- ~ ~ ----- ~ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.amc-list.com/pipermail/amc-list/attachments/20070622/563fda93/attachment.htm _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list