Consider it just an optional feature of the older indirect injection mercedes diesels. You know how hard it is to read the oil level in a modern car with the almost clear transparent oil? Mercedes made quite sure that certainly was not going to be an issue on their diesel cars.

Blacker than a witches ___ comes to mind. Figure out the three letter word if you have never heard the expression before. I guess I should give a hint. The first and last letters are both Ts.

History claims Rudolph diesel, the individual credited with the invention of the diesel engine ran them on coal dust at one point. His engines never forgot that particular abuse. Until the last while. Now some people are trying to burn anything they can in them once again it seems.