If you put an oil pressure gauge on the engine, you will never put 0W40 in there again. (Exception would maybe be a short-commuter in winter.)

5W40 is the MB recommendation since around 2011 and that's what I run. Back when I was running the Graphite really hard in hot, Georgia weather, I went with 5W50 - but it was pretty heavy below around 60F.

Every approved oil is on this list - the list changes over time, but right now, here is what MB says - notice the emphasis on 5W40:

https://bevo.mercedes-benz.com/bevolisten/229.3_en.html