Ran some of the $39/5 gal Sinopec T700 15W40 in both my 08 MB GL320 and my 99 MB E300. Neither car used a drop of oil between changes. Iron seems high to me but the lab report does not seem worried about it. I am wondering if 15W40 is causing extra wear at cold start. This oil IIRC was ran mostly during the summer, but during the winter we get down to teens frequently, sometimes single digits, and rarely 0 or below. I think I am going to run 5W40 and see how it compares to this sample.
This report is for the GL320
This report is for the GL320