The Mobil 1 V twin ^^^^^^is rated SG . Actually, Valvoline dino motorcycle oil is SG, too. I run it in the Monza. I get Motul 10-60 on Amazon for the Mighty Scura and AeroLario for around 11 a liter.
That said, my gut feeling is that the Mobil 1 15-50 is probably ok, but I'll stick with an SG rated oil. It's cheap compared to bourbon.