I have a friend who is pretty wise-
Had a transmission shop.
He checks oil level in every car so no issues happen on his watch.
A car was 3 quarts low.
He pours used oil in. A tech goes crazy - “man you can’t do that!”
Why not? It is better than the 3 quarts that are not in there.
Can’t argue - wouldn’t matter with him. He is hardcore.
#1 oil made is ENOUGH.
poured the fluid through a coffee filter
How do you know?
Are you concerned because this is a fresh engine? If so and you want elevated ZDDP for that reason, then run Valvoline VR1.