The better Shell Rotella T6 is also a universal oil usable in all engines, ( I have run it in our cars for years) however it’s not real widely available outside of the US, best to carry your own supply when you can.
I will probably go back to it, just because with one oil I can cover the outboard
, generator, main engine and Honda
, although regular Rotella would be fine too.
Many people who have spark ignition motors but run them very hard use Diesel oil, like the dirt bike crowd, because from a shear and stability point of view Diesel oil is more stable, and or better for wear prevention.
Like the article said, it’s the additive package in some Diesel oils like zinc that is also used as a TBN improver as well as anti wear, will poison some catalysts, but if your Honda
generator doesn’t have those catalysists (it doesn’t) Diesel oil is fine for them, same in my opinion for a four stroke outboard