I am running my Archer on Aeroshell 15W50.
The Lycoming 0-360 burns about a quart of oil every 12 hours.
I have a case of Aeroshell W100 and have no use for it and everybody at our
field uses a multigrade.
I was watching an Aeroshell video and was surprised that it implied that all
Aeroshell oils were compatible.

What is the Forums opinion on topping up 15W50 with W100.

Roy