Hi. Not looking to start an oil debate. I'm looking at an oil that lists zinc and phosphorus separately and am wondering how that converts to ZDDP in PPM. The zinc is 0.11% and phosphorus is 0.10%.

 

PPM = Parts Per Million

So 0.11% = 1100 PPM, 0.10% = 1000 PPM.

 

Ok but zddp is zinc and phosphorus so does that make 2100ppm zddp? Seems high.

 

Not sure how ZDDP is calculated but I don't think you add them up, but rather average them. I would look for the individual levels zinc and phosphorus as you have and decide if both levels are enough (do we really know? We all follow what's written in the internet and hope for the best).

 

No, they are always listed separate.

 

Ok so that would make this less than 1100 zddp which is borderline then

 

1100 / 1000 is fine and is what most oils were 15+ years ago before the CAT saving standards kicked in.

The "new" standard that has everyone worked up is less than 800ppm.