i often get lots of oil from a friend who works in a warehouse.
cases that have a leaker or broken box.
i had 5 odd qts on the shelf and hadnt got into the stash to get 5 that matched.
work van needed a change.
i used 1 m1 15w50,1 m1 ep 15w50,1 delo400 15w40,1 mc 5w20,and 1 redline 10w30.