After reading all of the negative remarks based upon "I Believe, I think or I heard it in Number 3 stall; I would like to give my opinion(another I know).
I have a 1987 300E spark ignition W124030.
It has 171,300 miles and has never had the cam cover off.
It still runs smooth and strong.
For calender year 2000, it averaged 19.4 mpg.
His oil consumption is 1 qt per 1100- 1200 miles.
He has had "Liqui-moly" added every 20,000 miles after the initial break-in period.
MOS2 burnishes the moving parts surfaces and is soluable with the motor oil, not like some other teflon additives that settle out in the crankcase.
The cost of the additive is zelch compared to the protection it offers.
So go ahead and make your personnal comments, I'll continue using this "snake oil" additive and look forward to 200,000 miles without even valve stem seals.
If some M/B dealers use MOS2, it can't be all that bad, or are they just spinning thier wheels and ripping off thier customers?
Happy Trails Beep Beep from Houston!!!
Donald, El Cheapo
Edit:
P.S. I failed to mention I add it to the differential lube as well. I change the lube every year(12mon).