Certain camshaft manufacturers themselves say to not use low ZDDP oil with their products because they will run lobes off the cam or dish out lifters. Now these are flat tappet cams. ZDDP is like many things in life, it is good in moderation. Most oil makers and even places that sell ZDDP boosters for oil tell you to not overdose on it because it can be detrimental, but most statements say that is around the 2,000 PPM mark. Many race oils, especially automotive ones like the awesome Pennzoil GT 25w50 are loaded with it.
And in my honest opinion....longer wear protection IS better wear protection
And in my honest opinion....longer wear protection IS better wear protection