Really good

Best oil additive on the market!

The engine flush left the top of my cylinder head squeaky clean. It was ridiculous. My car is a '97 M3 w/ 172k. I've heard the PO took care of it well, but I can't be 100% sure of that. I thought just to make sure I was getting off on the right foot with this car I'd run this flush through and pour in the additive after the oil change. So maybe it was fairly clean before the flush and this just helped it be more so. In any case, after I popped the valve cover I was genuinely astonished. Jury is still out on the additive though, not enough time to really make a good conclusion.

I used Liquid molly oil and read not to mix the MOS2 friction treatment with it, so I didn't. However, I did use the engine flush with no issues!