A good quality synthetic does not break down like a dino based oil. Thats why people can go thousands and thousands of miles on the same oil. This is well documented and backed up with oil analysis. The bypass filter is a good idea even if you don't run synthec oil or want to run your oil forever. Cleaner oil(NO soot) = longer engine life.

rr, when you change filters at whatever interval Blackstone tells you to do, you always add or top off after replacing the filters which is usually aroung a half gallon of oil so you keep replacing the additives you mention. It works for big rigs and machinery so it works for us also.
Bud

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1987 300D Turbo, 175k mi., 1998 BMW 323i Convertible, 1997 F250 4x4 7.3L PSD

Soot is sub-micron particles. Very few filters will actually remove soot. Diesel rated oil has additives to keep the soot in suspension or from "agglomerating" which is a fancy way of saying sticking together. As long as its not sticking together to form larger particles that can do real damage its not a problem, up to a point. Most oil analysis labs allow up to 2% soot as a maximum. Most of the time the concentrations are far below that.

A bypass filter is still a good idea if you want the engine to last as long as possible. However, these engines seem to last 300K with ease without a bypass unit. Most of the time the body rots away before the engine gives out. The neatest thing about bypass systems is the extended oil changes and using less oil overall. Thats the true benefit regarding MB's with bypass systems.

RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

I saw a video a while back that had black dirty oil pumping through a clear canister to simulate a normal oil filter, then they changed the flow to include a bypass filter simple. The oil became clean, no black soot. There really isn't a negative effect to using a bypass filter. Baldwin has a spin on filter that is $6 that is rated at below 2 micron. Total cost of installation should be below $50. Cheap insurance.

I know the video well. I believe the system is called the FS2500 or something like that. I can tell you it is NOT cheap. A Baldwin 2 micron filter will not remove the soot from the oil. Thats not to say its a bad idea to have one! You are correct that its a cheap way to keep the oil much cleaner. I'd go for it too but I have other expenses right now. RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

....We used to run Baldwin filters on big John Deere tractors back in the mid 70's.....I have watched a lot of discussion about oil bypass filters pro and con....
I admit to being one of those unsettled, strange people that just likes to see my oil that golden amber color...I grew up with diesels and know that they are carrying a soot component and it is ok for the oil to be black...But it just goes against my grain to see it black...this is one of those things that will give me happiness as I observe the clean oil.....the unreasonable happiness and contentment alone when I check the oil level will justify me getting one....or two......

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1978 Yellow 300D (The Mustard Toad)
1980 Blue 240D (The Iron Toad)
1989 Grey Mitsu.4WD Mighty Max Pickup (Needs a Diesel transplant bad)

(Open the pod bay doors HAL)

Click on the link in my signature.