Its either I use a straight 30, 15w-40, 10w-40, 10w30, or 20w50.
I wouldn't use 5w20,0w20,0w16,5w30,0w30, 5w40, and 0w40.
The ones i wouldn't use is through testing each one using briggs engines with very high rpms adjusted on my pressure washer and push mower,
the 5w20 after 20 minutes started burning like CRAZY, the 0w20 started burning at startup and created blue smoke you can see everywhere, 0w16 fouled up my plugs, 5w30 ran for 1 hour and then started burning alot, 0w30 fouled up my plug after 4 minutes of runtime, 5w40 seemed promising at the 2 hour mark, but after shutoff was as thin as water, 0w40 started burning alot at startup but then stopped after a minute.