optimax
Can't speak for anyone else but both myself & my lad both put optimax in, This stopped the pinking that we'd both noticed on motorway ,pillion+fully loaded at 80mph ish when accelarating hard.Shaun at Rainbow told me to try it, I now use 2 tanks of unleaded to 1 of optimax or super if touring heavily loaded. result no more pinking.
Ps Pinking was worryingly noticable if wearing open face helmet
Just use if when necessary