
This is the second UOA on my son's truck.
Rotella T 5W-40 synthetic
About 4900 miles.
Wix filter used.
No makeup oil.
The first one is here -
http://home.illicom.net/users/jsharp/personalphotos/OA/New_Nissan_oil_anaylsis_1.jpg
The Rotella looks like it did OK this time. The lead is down a little maybe but the rest is pretty similar to before.
I don't understand why the silicon is this high. I checked all the intake plumbing, pcv system, vacuum lines, etc., the filter is almost new and seems to seal OK in the Airbox.
I think the 4.83 TBN looks OK for this mileage, especially after looking at the Blackstone numbers for so long.
I also don't know what's happening to the viscosity. The last UOA had Motorcraft 5W-30 blend sheared to a 20 weight in 3K miles. This time the Rotella has sheared to a high 30 weight. No fuel or other things that might contribute to it other than I did add 4oz of LC about 2500 miles into this run. I don't get it...
Comments?? And can anyone clue me about how the soot, oxidation, and nitration numbers might compare to the total insolubles that Blackstone shows?