Diabolis

That's right - see my post #44 above (https://mbworld.org/forums/5802431-post44.html). Confusion I may haz had it.

Ingenieur

gotcha

Valvestud

It's interesting how we make this so complicated. 229.51 is the latest spec and is the MB recommended spec for the M156 engine. But the previous 229.5 is also still valid for our engines.

Regards,

Joe

Diabolis

Hi 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

Ingenieur

looking at the bevo site there are no .52 currently available in 0W40 or 5W40...yet

marvinlee

I can't speak to the M156 engine, but my owner's manual for the 2014 MB E550 4matic with the M178 V8 allows a variety of oil viscosity combinations. See the chart on page 425 (of my English-language manual, Edition C 2014, Order no. 6515 3576 13, PN 212 585 83 00).

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.