Because I buy what's available on area store shelves. As it is, I had to go 50 miles one way for the last 0W40 Euro Car Formula I bought. If anybody sold the 229.51 around here, I'd buy it. So since the owner's manual in my pro-ULSD car says 229.5 ECF is ok, that's what I buy. No way I'm paying hazardous freight charges having 229.51 shipped from beyond reasonable driving distance.
"Supersedes" is your word though. If it was Mercedes' word, there'd have been a letter in the mail telling me to ignore my owners manual = and only use 229.51 spec engine oil. So far that letter hasn't arrived.
And for those that don't mind abiding what their owner manuals say, here's that pg12 bit about fleece filters that I mentioned originally. I've got one installed in the car, and I've got a new one on my parts shelf. It sure don't look like paper, so I'm taking it on faith that it's fleece.
Take the time to read the MB229.51 technical specification some time...BB00.40-P-0229-51A
When was the last time Mercedes took the time to mail you about a service bulletin???
When was the last time Mercedes Mailed you a revision to your owners manual???
When was the last time Mercedes sent you an advisory regarding a change in technical Specifications?
See my point?
Unless YOU are a dealership you're not going to hear BOO from Mercedes regarding any change in specification.
All the manuals in your car were out of date the second after they were printed...Sorry but thats just the fact of the technical side of the automotive industry. Don't hang your hat on some 5 year old publication found in your glove box, rest assured it's no longer up to date and except for how to work the electric door switches probably not even applicable! THis is the part where they want you to rely on an offical source ie your dealer to stay up to date on these changes, vs sending you a new owners manual every other week with the latest technical information.
And, did you really think MB was going to mail a letter to every owner with an out of date manual? In case nobody has told you this, they aren't going to send you a stamped letter to tell you that
MB229.51 was formulated at the beginning to SUPERCEDE all previous oil specifications for diesel engines. This allows dealerships and service centers to stock a single type of Diesel engine oil and reduce the risk of using an incorrect specification in a newer engine. You don't want a dealership using MB229.5 in a DPF/SCR engine!
The goal from the onset was to have a single blend oil that covers all previous MB diesel applications and MB Sheet specifications. The considerations when using these oils are:
"The temperature ranges in the viscosity classes must be observed"
"Use in combination with low-sulfur (S < 50 ppm) or sulfur-free (S < 10 ppm) fuel! If fuels with sulfur contents of S> 500 ppm Approval are being used, the oil change intervals must be reduced!"
The MB oil filters for diesels use a different media than what is used in gasoline engines. The media has a technical specification that requires it to be suitable for up to a 50,000km service life in cars, 150,000km's (not a typo) in HD applications, it is yellow in color to distinguish it from the fleece filters so as not to confuse the two. The primary difference is chemical resistance that leads to embrittlement of the element under high temperatures.
Diesel Engines and where MB229.51 approved by MB for use:
Retroactive applicability for 229.51 apply to engines with DPF filters:
OM 629, 639, 640, 646, 647, 648, 664, 665
OM 639 in model series 639 and 906, Other OM 6xx with DPF not listed above
Retroactive applicability for 229.51 applies to engines without DPF filters:
OM 660,OM 640, 642, 646 in model series 639 OM 646, 647, 648 OM 611, 612, 613, 628, 639, 668, 664, 665, Other OM 6xx not listed above.
Also 229.51 covers:
M 112, 113, 134, 135, M 266 Turbo, M 271,