We won't see Leak-Free til they come out with the Oil-Less engine
Some day, MB will design an engine that is lubricated by German air.
You know, by definition, a fluid is something that flows. So oil and air both fit in quite well into that definition.
Plus, German air has one outstanding characteristic when compared to oil, dino or synthetic.
It has an infinite Viscosity Index (VI) as its viscosity doe not change with temperature. So it does not thin out like oil. Using German air, the cars gets the lubricating air as soon as it is started and then it maintains that same viscosity at operating temperature.