The link for the article in the August 2006 issue of Hot Rod Magazine concerning the reduction of the proven antiwear additive zinc dialky dithiophosphate (ZDDP or ZDTP) in engine oils follows:
http://www.oldgmctrucks.com/photos/FlatTappetCamTech.htm An article concerning new diesel engine oils:
http://www.machinerylubrication.com/arti...%20and%20Trends The modern diesel oils with optimum levels of ZDDP are rated "CI-4" or "CI-4 Plus". The recently distributed new diesel oils with lower ZDDP levels are designated with the new "CJ-4" rating.
