Question....How does the right stuff get in the oil?....added at the refinery?,,,,,I don't know..just asking....Or is the zinc crap occur naturally in crude?
I believe ingrediants are added. I use the ZDDP MAXX. I add it to the 5 qrt oil container of Quaker State Defy (which already has a little more zinc in it). I get the oil at Walmart. 5 quarts for 15 bucks, then add the ZDDP MAXX I get off of ebay.