Re: Royal Purple motor oil - other synthetics

Posted by Owen_Dyneto On 2016/5/11 13:13:50

Not that Packard engines require any zinc (ZDDP) with their soft cam loadings, but yes it's still present, reduced from about 1300 ppm in the older CI-4 formulations to about 1000 ppm in the current CJ-4 forumulation.