Interesting I see no one care about the WSS-M2C925-A compatibility here.
I personally think its important to get a match! only the Mobil 1 Extended Performance 5W-20
and the Castrol Edge A1 Professional 5W-20 meet the specs!!!! Of the 2 only the Mobil1 seams to be available to the public here in the USA.
Remember 5W-30 is thicker and fine, if you live in 90 Degrees weather, but not where it gets cold!
The question is how much damage you do long term with a wrong or cheap oil!
The engine tolerance are much tighter these days, the piston rings on the other hand have much less tension on the cylinder walls than on a cast iron block engine.
That results in more buildup of goop in your engine with usage of a too thick or cheap motor oil. Long therm it is like you would put honey into the oiling system, causing less freely movement and more stress on bearings and internal moving parts. Who is to say what could happen, I personally don't wanna find out, so I stick to the oil specs as recommended by the manufacturer, no thinner no thicker and no other detergent additives!