The manual for my Honda 4 stroke mower contains the usual advice about oil
(paraphrased here): You can use oil that meets blah-blah-blah specs, but we
recommend Honda oil. When I see stuff like this, I assume they mean "If you
visit the mower shop, you might buy something else so we think you should go
there for oil". I like supporting local businesses, like the one that sold
me the mower, but could there be anything special about Honda oil?