I kinda get the impression that most guys are running the ZDDP additive. When I first started hearing about all this it just seemed strange to me that it seems like there is only one comnpany making an additive. Most of the articles I've read quote ZDDP plus' info. And I'm sure they want to sell their stuff. But I also believe that the oil manufacturers are changing the additives in oil because of environmental reasons. Makes sense. I don't mind spending the extra $$'s for an additive to keep my engine safe if its necessary.