Keep telling yourself that diesel oil is good for you. Because it's not.
I'm not a tribologist but I have been dealing with oils since before I switched to alcohol fuel in 1988. We had issues running alcohol with certain oils. So I needed to figure out why.
You are far too fixated on ZDDP and how many PPM you need. Like I said, more is NOT better and the minimum PPM you want to know is based on base oil selection, intended use of the oil, fuel being used and any OTHER secondary lubrication regime the tribologist may use.
Zinc is a consumable. So is the phosphorus that makes the zinc work. Certain base oils may not do well with a certain PPM of zinc. So they adjust the additive package to account for that.
One oil may only need 1200 PPM and another 1500 PPM to do the same job.
Buying an oil based on ZDDP PPM is like buying a cylinder head or carb based solely on CFM ratings. Don't do it. But you will because people swear by diesel oil.
There are far more important factors than ZDDP percentage.
