MAN things sure change.
On my 1999 E-220 CDI the service interval is 20000 km's /12500miles. I have asked the dealer about changing oil inbetween the intervals, since I think it is a awful long time to run the same oil. Especially since I haul a 1900kg / 3500Lbs camping trailer on my summer vacation which really put a lot of strain on my engine, but they say it is a waste of money to change oil inbetween. The service indicator thingy takes into consideration all aspects of your driving, and a guy hwo drives very carefully can get over 20000 km's between services while I who haul that big trailer will only get like 18-19000 between services
Go figure