Well, that oil started its journey in to your crankcase 230 million years ago, so I mean really........... what's 82 more years??

 

The real question is: Would you put V twin oil in your airplane and fly it????

 

No, for the same reason you should not put aircraft engine oil in your motorcycle.

 

Let me rephrase that. 30w oil was the only oil that was called for in any of the late 50’s and 60’s engines that I owned or worked on.
it was the same for atf, it was the red stuff for all those cars too.

 

HD had no idea how oil technology would evolve.