OVERKILL
$100 Site Donor 2021
The thickening happens because of oxidation. This particular oil seems to shear some of its VM's early on in an OCI and then oxidize a bit, bringing the visc back up a little later on and then stabilize. I'm not sure as to WHY it behaves in this manner, it just seems to.
You can't use Blackstone's "should be" figures to determine anything here. So what they have for SUS, without a measure of what the oil was in the first place, you have no idea where it is relative to where it actually should be.
This is why the 100C cSt figure is more helpful, as we can use Mobil's PDS for the product to see what the product was when it started, which, as we can see, was a bit heavier.
That said, as I noted, we also have to take the measured figure with a grain of salt, as there have been some visc discrepancies with Blackstone lately, so we don't REALLY know if it actually sheared that much, or if there is some measurement error there.
What we do see (since you didn't get TBN unfortunately) is that there is nothing unusual to cause concern about your UOA here. It looks excellent. There is no sign of contamination with coolant or fuel, no high silicon, indicating that air filtration is also good. If you had also got TBN, we could get an idea of how much useful life was left in the product, which would allow us to approximate what sort of OCI you should be looking at with it.
That's what UOA's are for: Determining OCI length and monitoring oil/engine health by watching for anything unusual that might pop up.
You can't use Blackstone's "should be" figures to determine anything here. So what they have for SUS, without a measure of what the oil was in the first place, you have no idea where it is relative to where it actually should be.
This is why the 100C cSt figure is more helpful, as we can use Mobil's PDS for the product to see what the product was when it started, which, as we can see, was a bit heavier.
That said, as I noted, we also have to take the measured figure with a grain of salt, as there have been some visc discrepancies with Blackstone lately, so we don't REALLY know if it actually sheared that much, or if there is some measurement error there.
What we do see (since you didn't get TBN unfortunately) is that there is nothing unusual to cause concern about your UOA here. It looks excellent. There is no sign of contamination with coolant or fuel, no high silicon, indicating that air filtration is also good. If you had also got TBN, we could get an idea of how much useful life was left in the product, which would allow us to approximate what sort of OCI you should be looking at with it.
That's what UOA's are for: Determining OCI length and monitoring oil/engine health by watching for anything unusual that might pop up.
