Castrol SynBlend for the first 2 and Castrol Edge for the 10k run…
Haha, Mobil, good one
…
Comparing same mileages to my 2005 3.5L the iron number are very close (except for the 10k run @ 49) and seem to be on the same upward trend.
i ran Mobil in my 05 for over 138k miles, so i'm giving Castrol a try, was hoping to see a little better results also. back to a GM PF61E filter … thinking the same thing about TBN and iron, will see on the next test...
Blackstones comments ...Nice turnaround! There's nothing highlighted to talk about here. Aluminum has dropped back
down to normal, and while iron is a bit higher than we were seeing back in 2013, it is reading within the
average range now (and that counts for something). Maybe it'll improve again next time. Sodium is back
down to normal as well, and no fuel or other contaminants were detected. The TBN is back above 1.0,
reading at 1.4, so there's still a sufficient amount of additive left in the oil to run longer. This 3.7L is looking
good at 55,500 total miles