4th UOA, 07 Yukon Denali w/6.2L, 8600 mile, Mobil Delvac 1 ESP 5w30

[iamdub]

I like the 5w40 results and formulation better than the 5w30.

There are differences in the two Mobil Delvac 1 ESP oils. Here's "virgin" results that I found:

5w30 & 5w40

Aluminum 8 2
Chromium 0 0
Iron 1 0
Copper 0 0
Lead 0 1
Tin 1 0
Molybdenum 0 50
Nickel 0 0
Manganese 0 0
Silver 0 0
Titanium 0 0
Potassium 0 1
Boron 78 134
Silicon 4 4
Sodium 3 9
Calcium 1170 1126
Magnesium 845 973
Phosphorus 756 1159
Zinc 819 1343
Barium 0 0
TBN = 11 10.2

Agreed. Zinc, Phosporous and moly are the good stuff and the '40 has more of it and showed lower wear metals in your UOAs.