I have a intek206 5.5hp, with many hours on it.
I have used both oils in the past, and will in the future.
These small engines will run on anything you choose to use.
My small engines often get left over 0/5w-20, 15w-40, hdeo sae30/40, 20w-50, 25w-40, 10w-30/40, you name it.
Never a oil related...