Is this ZDDP? Zinc dialkyldithiophosphate If so it is in Redline Motor Oil On May 14, 2012, at 7:11 AM, Dave wrote: > last time I was in a flaps, the valvoline synthetic 20w-50 racing oil had zddp > Bill Pugh 1957 TR3 "Casper" TS16765L Wallace, CA anabil007 at comcast.net