Can't help with the emission designations.

However it seems Mobil 1 comes either as ESP 5W30 or ESP X1 0W30 and both of these meet both 229.51 and 229.52 specs. Should be available on-line or elsewhere for $9/qt or less?
I saw Mercedes oil on Amazon for $52.50/6pack which is also about $9/qt.
https://www.amazon.com/Mercedes-Benz-5W30-Synthetic-229-52/dp/B00R0CRISI

My 2014 GLK250 called for 229.51, but now dealer uses 229.52. Both have same low ash content. Don't know what else is different.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5