It is my understanding that the EPA at some point mandated that a mixture of zinc and phosphorus known as ZDDP (Zinc Dialkyl Dithio Phosphate) be reduced or eliminated as an additive from motor oils because it is damaging to catalytic converters. I am interested in this issue because I have older cars (1960 Olds 1991 Volvo) with the original gasoline engines, and I have a number of older quarts of motor oil. I have a couple of questions about this:
1. Was zinc phased out of motor oil, and , if so, when was it eliminated? 2. Was it reduced/eliminated from diesel rated oil? 3. Is there a way to know from the writing on the can how much zinc it contains? 4. Is there a way to determine from markings on the can the age of a given can of oil? 5. Does canned/bottled engine oil have a shelf life? 6. Should a container of older motor oil be shaken to mix the ingredients before being poured? 7. Would cans of "STP" additive from the seventies and eighties contain zinc? 8. Is the "zinc" issue one I even need to be concerned about? 9. Would an old (70's era) can of racing motor oil contain a greater amount of zinc? !0. Might this topic have already been discussed in a previous thread? Jerry 82 240D _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
