Strange engine oil level readings

[n86121]

Years ago I drilled down on this: Why 12 qts when it is happy w 6?

For certification, the engines have a max allowable oil burn rate.

At that max allowable oil burn rate,
when the aircraft on its longest flight,
it must still land with enough minimum oil.

So the max endurance of the airplanes increases the oil requirement.

Ta da!