Like Big Red, I was checking out of this thread, but, the idea that when you buy parts from and MB dealer for any car they provide parts for and you have no right to expect the quality to be checked and standards adhered to is just not realistic. There are people employed to see to it that when a supplier puts the parts in the MB boxes they meet the MB standards. They come with MB warranties.

As for the filter media, you need to understand Germans, especially Germans in post WWII Germany. Exotic materials for replacement parts were not economical, and while a new MB was more expensive than a new VW, luxury to Germans in the 1950' through 1980, at least, was rugged reliability achieved with low cost of ownership. MB Diesels were used almost exclusively at that time for taxi cabs. These are the people who waged a war on the world with next to no natural resources. Raw cotton and "floor sweepings" were likely very cheap and determined from experience to provide adequate service in a by-pass filter, and the benefits of a by-pass filter were also likely documented by experience.

Germans were frugal then. They rarely had adequate resources and usually had to figure out how to get jobs done with alternate solutions that were frugal and in plentiful supply.

I have no data to suggest these filters are substandard so I use them without any reservations. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)