To obtain that milage interval you MUST use an oil that complies with MB spec 229.5 any other oil can't do the distance.

If you closely read MB sevice info they state that drain intervals must be shortened when using high sulfer diesel. I don't know the sulfer levels in US but in Australia they are still relativly high so the drain interval sould be shortened to 15,000km/10,000mi.

Personally I stick to 6000mi on my 87 diesel even thoguh I drive alot 7 days a week, if I had a CDI i'd do 15,000km/6months (both with mobil 1).

Oil is cheap, engines aren't.

If you drive short distances with cold running then shorten the interval, if you sit on a freeway all day then extend it. You have to judge you're driving conditons too.

__________________
Alex.

MB Tech
Sydney, Australia
Volvo 122S
W201 190D 2.5 manual
W202 C240
W203 C32