Originally Posted By: Duffman77
Oil is Shell Rotella T6, CJ4 in 5W40.
I assume you just tagged onto your old UOA with an update.
It would be easier for those who use the search feature if you would post new UOA data in a new thread each time. Your history is already in the succesive UOAs.
So the oil hours is km's = 7.5k miles. OK - got that.
Would the CMU/SMU be 98.x km's in total duration? Roughly 60k miles or so, total for the vehicle?
Regardless, looks fairly normal for a PSD with 12k km (=7.5k miles) on the oil.
Fe seems to track with the vis, but only loosely. Not so much the starting virgin vis on the container, as they are all 40 grades, but the vis as it relates to accumulated exposure. As you accumulate longer runs, the oil seems to shear and the Fe seems to track with it. IN NO WAY is the Fe count bad or alarming; just a note of how you can see some correlation regardless of which multi-grade you use. (Fe is also cumulative in the lube; don't forget that.) Typical shearing in a PSD. Nearly every UOA I've seen with HEUI shows shearing eventually if a 40 grade is utilized. However, using a 30 grade from the start rarely results in much, if any, shearing. Almost as if the HEUI systems simply prefer it. That shearing effect also seems to have minimal effect on wear other than Fe. Bearing, upper end and ring wear (Cu, Pb, Al, Cr) all seem to stay fairly consistent.
Overall, a decent, if not unexpected report.
I see you've bounced between 0w-40, 5w-40, 10w-40, and 15w-40. And yet the wear overall (Cu, Pb, Al, Cr) all seem very consistent. And the Fe is not all that bad in variability either. The Fe is probably a combination of the vis degredation and also exposure, which obviously go hand-in-hand. This shows that the engine really does not have a great affinity for any particular brand/grade.
As you have the willingness to experiment with brand/grades, I would suggest trying one of two things:
1) consider using a 10w-30 year round. The lighter grade really helps with the "romp" on very cold starts, and yet there are plenty of UOAs to show that this lighter grade protects just as well as the sheared 40 grades.
2) consider using the least expensive dino or semi-syn you can find. All your OCIs seem to be around 8-12k km (5-7.5k miles). That is not really a reason to use syn's. I would presume you're using syns to either assist in the cold starts and/or because you believe it might result in less wear. But ...
Your UOA data is showing you that the engine really does not care what brand/grade of lube is used, nor does it have preference for base stock. You might as well use a good quality light grade dino oil; you'll get good starts, good protection, and spend less. After all, you're paying for the data; why not listen to what it's telling you?
