2nd What Jarrod says!
ZDDP is a tough nut to crack cheaply though, so if you want to consider an alternative (and not have to worry about government regulation making you chase ZDDP or equivalents around,,,)
A while back I did some research into Rotella which has always had a very good reputation for trucks and other hard working engines that can produce a lot of wear. I have been using this for a while now with great results apparently. And you can get it at Wal-Mart in large containers. Rotella T triple protection - 15w 40. It is Shells replacement for their oil that had the additives we need, but that they are no longer allowed to produce. Reading their material on it is seemed logical and the weight is right as well. They have a lot of info showing wear results when tested against ZDDP formulations and it was even better. Be SURE to read the containers closely as there are slightly different Rotella formulations in the store! Do not get the wrong one.
All can say is that it is easy to get, relatively inexpensive, never uses any oil between changes,, and the engine purrs and car runs like a scalded cat.
1983 928S - 16v 4.7L L-Jetronic
Dark Grey w/ Blue Leather
85/86 exhaust manifolds
SS Hi-perf Cat
Air pump delete
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