Well, I admire your tenacity with trying to find the 'AHA' moment with oil ratings. However, I really don't see any need to worry about the E-Class, or any other vehicles. There is no AHA moment because there is nothing wrong with using MB-Approval 229.51 or 229.53, or any oil that may not have the "MB-Approval" designation but will still suffice.This is a very interesting statement. Again, please, with my respect for you:
This is premised on the "assumption" that some new gasoline emissions technology has come about and has been applied to the 2016 smart fortwo, something along the lines of a DPF for diesel, which would necessitate the creation of a new specification, in DPF's case a 229.51 specification category.
I would think they would apply the same technology to the new 2017 E-class.
I attach the 2017 E Class (US) manual for your reference:
and direct you to page 347
The specified oil for all gasoline models is 229.5, 229.6
If none of those are available, "a maximum of 1.1 US qt (1.0 L) once": 229.1, 229.3, or ACEA A3 (and this is 1.1 qt in a minimum 6.9 qt system)
My milder side that stated 229.51 would be fine in the M 281 for 1 year 10k miles is now switched to a feeling one should drain 229.51 and fill with the proper oil.