Looks like you should get some zinc additive if your breaking in a new engine. Zinc is being removed from most oils now because it is not compatible with catalytic converters. http://www.joegibbsracingoil.com/news/060316b.php http://www.compcams.com/information/whatsnew/NewsDetails.asp?ListHistoryID=288972762 I also read that AC Delco has something called 'EOS oil fortifier' that also has zinc. However, I read the new formula has had the zinc removed - not sure if this is true or not. Some race motor oils still have zinc, especially those that say for use with flat tappet cams. Shell Rotella supposedly still has zinc. Or is this all hogwash? What do you guys think?