Joe,
There is no such thing as a dumb question.

Modern oils are still graded the same as they were 30 years ago for viscosity.
While we have advanced a little from the specifications of many years ago, moving from CC to CJ or better, each change tends to be just an additional requirement, not a new specification. It is a myth that in moving to a "more modern oil" one should change the viscosity of the oil. The viscosity requirement is part of the design requirements of the lubrication system as well as component design such as bearings. Small changes are unlikely to have a catastrophic effect as lube system design is normally substantial over design.
My posting the page was to make sure that people know what MB required. It definitely was not aimed at you! Unfortunately many never read instruction books. Just watch kids opening presents. I am sure you are not a kid though!! The last thing they look at is the instructions. They normally get thrown out with the wrapping.

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving