I just read
https://stlouisncrs.org/news_files/St_Louis_NCRS_Chapter_July_2011.pdf
and man is that packed with great info! I also spent some time on the "Bob is the oil guy" forum, and some of the posts read just like the above article. I have pretty much decided to run the 15-40 oil in my car. I have not gotten a look at the label on the barrel, but I will check it out. I am sure it meets all the proper specs, as it is used in all my friend's cars and trucks (mostly Mercedes-Benz Diesels).......Rich