Now I knew that topic subject would get your attention I changed oil in our Mark VIII today and replaced the Citgo 5W-30 with ARX that was in there for 2,700 miles with a batch of Schaeffer's that I had in the basement for the rinse cycle. So I open the Schaeffer's bottles (I had never used that stuff before) and started pouring it in the engine. WOW, what a surprise!! That stuff is as green as GC, maybe even greener AND !!! it smells just like the GC I have. Some people here call it like "Gummi Bears", but I don't smell gummi bears out of that distinctive smell and I grew up in Germany. The smell of the Schaeffer's is however distinctively different than all the other oils I have used AND is identical to the GC I have. I opened a GC bottle and a Schaeffers and held them in each hand doing a smell test. They are the same.