Merc doesn't make any oil, it merely repackages it (or more accurately, it
has
it repackaged for them).

Exactly why I wonder if all of the "automobile" advice applies to marine
outboards. This is oil made for the auto industry where the "starting" range is
0f or below to a normal operating temp of over 210f (what most auto thermostats
run).
That is an operational range of 200 degrees or so.
Outboards seldom start below 70f and it is closer to 80 most of the time here.
The thermostat is 120f.