quote:
As I mentioned using additives and not having a reference oil affect the FTIR readings in an unpredictable way. When your report first went out we didn't have the reference oil loaded so our program strips out the numbers because the values it gets from an autoreferenced sample (the procedure we use without a reference oil) are just plane wrong and only have a 1 in 4 chance of being right. We should not report the value when people use additives either because there is also a high degree of uncertainty, however like yourself, people demand that we do things that are not always in their best interest so we gave you the numbers even though they are not accurate. You should ignore them.
As for the viscosity I would not worry about it. In theory your calculations should be valid or at least when combining oil, however the additives may act differently. As a rule we don't advocate the use of additives and I have never seen a measurable difference when one is used with the exception of viscosity changes. Cat has an STP-like oil that is used in special cases but that is the only one we prescribe. Since our goal is to help our customers get lowest operating cost (not just fuel and lube but total ownership costs), the additives do not justify their cost.
The particle count is completely normal for a gas engine. This is what we call a baseline high error and all it means is that the oil is too dark or too opaque for the laser to past through. We have to do a dilution on these samples and that's why we charge extra. We can run 1 particle count per minute for non-engine samples but takes about 15 - 20 minutes to do the dilution and even then we are not always successful.
Now for the good news, your filter is doing a very good job. I ran a microscope exam and it shows no metal particles at all and very little of anything else. The copper is a little high but there is no copper wear particles visible so this tells us it is not wear but instead a chemical reaction that could be caused by the additive. We see elevated copper when people switch brands of oil or when the oil additive package is changed so it stands to reason that when you add something to the oil it could drive up the copper. The changes affect coatings on copper parts so it is not harmful.
