There seems to be some confusion about which octane is really needed for the Ryker (maybe it is just ME that is confused).

Ryker Manual page 37 states:

"Use regular unleaded gasoline with a minimum AKI (RON+MON)/2 octane rating of 87, or a RON octane rating of 92. The USA uses the (RON+MON)/2 number whilst Europe (and others) use the RON rating. This means a Ryker will run perfectly fine on 87 all day long.

All higher octane/way more expensive fuel will do, is reduce or eliminate any "pinging" during hard acceleration. Nothing more. It will NOT increase MPG, no will it give you more HP. Plus, unnecessary higher octane pollutes more.

Literally EVERY Ryker owner who has never tried 87, should! They very well could be pleasantly surprised!

In the Manual, where it says "For optimal performance use.... 91 octane", they are only talking about possible engine pinging.