M.B.DOC:

Given that this engine has 425K+ miles on it, do you have any idea what kind of oil change regimen this owner used? Did he follow FSS? If not, how often was oil changed? Was synthetic oil used for oil changes?

I am sure there must have been a lot of highway miles driven given this kind of mileage, which reduced the number of cold starts and wear on the engine, but I am just curious since I own a 2000 ML 320 and a 2002 E320 4MATIC both with this engine.