Yes, another oil thread...


Regards,
Joe
This is what I was trying to explain in my previous post. Unlike software revisions for example, 229.51 is not a later spec of 229.5. 229.51 supersedes 229.31 (oils that were originally approved for diesel engines), whereas 229.5 supersedes 229.3 (oils that were originally approved for gasoline engines).
In the past, 229.5 and 229.51 oils were mutually exclusive - the first was for gasoline and the second for diesel engines only. Recently, MB approved the 229.51 spec for use in their gasoline engines as well, but the 229.5 spec is still better for gasoline engines due to the higher ash content and HTHS values. Mobil 1 0W40 is a 229.5 spec oil whereas Mobil 1 Formula M 5W40 is a 229.51 spec oil.
There is an old thread on this board that discusses this in more detail at https://mbworld.org/forums/c-class-w...il-change.html.
I am not familiar with 229.52 so I can't comment on it, but it's also a low ash formulation so likely better suited to diesels than to gasoline engines. AFAIK the only Mobil 1 oil that meets the 229.5 spec (the "better" one for gasoline engines) and approved for the M156 engine is the 0W40.
Cheers,
Doug
Last edited by Diabolis; Oct 7, 2013 at 07:42 PM.
Above 23 degrees Fahrenheit, Mercedes permits the use of 0W-30, 0W-40, 5W-30, 5W-40, 5W-50, 10W-30, 10W-40, 10W-50, 10W-60, 15W-30, 15W-40, 15W-60, 20W-40 and 20W-50, fourteen viscosity combinations in all. There are increased approved-oil viscosity restrictions for colder temperatures.
As to Mercedes-Benz knowing all, I believe they have good but still imperfect knowledge of oils and their usability on M-B engines. Few factory and laboratory tests can perfectly duplicate the diversity of experiences that engines undergo in real life--sometimes over many decades.
I currently wonder why Eneos 0W-50 oil is not Mercedes-Benz 229.5 approved, though a review of Mobil 0W-40 versus Eneos 0W-50 specifications provides some possible hints.
Do your own thing at your own peril and don't ***** about the cost when you pop an engine.
I use Valvoline 5-40 (229.51 spec) and add ZddPlus. ARP studs, SLS buckets, and adhere to the 80deg C. limit religiously in all my M156 Benzes.
The Best of Mercedes & AMG

Replying to a grave thread from 2013 that happened to have gone cold 11 years ago with the answer (everyone knows) is.... silly.
EDIT: If it's an old thread with a niche problem that the OP never reported back on with the solution (which happens a lot), and no other solutions for said problem could be found. Sure, dig it back up since someone else may have had and fixed the problem.
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