I'm another one in the 'whatever I have around' camp. I've had no-name 5w-30 semi synthetic in my 24hp Briggs intek for around 40 hours (2 years) now with 0 smoke or consumption. I had never run 5w-30 but it doesn't seem to mind it at all. I will probably go with a 15w-40 for the next run since I have some in the stash. I've got a Fram Ultra XG3614 on there and I've been wondering how long to leave it on. I"m leaning towards 100 hrs.
I use amsoil small engine oil
How many decades between OCI?
its not advertised as an extended drain oil. Amsoil says to run the OCI at manufacturers recommended hours.
Its $7.35 a quart.