Wear Metal Ranges

Not easy as each engine builder and each transmission manufacturer will have different max wear metal guide limits.
These limits will be for a normal oil drain period.
Anyway trending usually more important than fixed limits to pick out potential wear problems

Manufacturer does have their own limits but not always. However, quite often, these limits does not apply at 100% to current customer application. This can be caused by differents factors, like for instance difference in sampling frequencies but also particularities from process and working environnement.

As Mr Davies said, tis wil not not help you picking potential wear problems.

Thus, the best would be to make your own limits based on the data you have obtained in the past. For each element, the new limits should be set by applying the following rule.
(this is proposed in Oil analysis basics by Drew Troyer and Jim Fitch)


Abnormal = Average + standard deviation
Crticial = Average + 2 standard deviation

Variation higher that standard deviation between each analysis should be considered suspicious.

I have applicated this rule in my companie this is working great.

I hope this helps.