Agreed. The risk of damaging the oil cooler and/or its lines does not justify draining that last pint of dirty oil and even if you did, the new oil will turn black almost immediately.

Mobil-1 TDT 5W-40 should be good for 10,000 miles, especially if you do an analysis occasionally. Our '96 E300D (W210, OM606NA) has Mobil-1 TDT 5W-40 in it and is driven about 8,000 miles annually. I change oil and filter once a year. The oil analysis typically comes back with "low" soot (Associated Laboratories doesn't provide a % number) and otherwise looks pretty much like new oil. I just changed the oil and have a sample on my desk waiting to go off for analysis.

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970