Honda CMX500A 2019 Owner's Manual page 46

Refuelling
Ignition key
Fuel fill cap
Do not fill with fuel above the level plate.
42
Lock cover
Level plate
Fuel type: Unleaded petrol only
MA, V, FO type
Fuel octane number: Your vehicle is
designed to use Research Octane Number
(RON) 91 or higher.
IN type
Fuel octane number: Your vehicle is
designed to use Research Octane Number
(RON) 88 or higher.
Tank capacity:
11.2 L (2.96 US gal, 2.46 Imp gal)
#
Refuelling and Fuel Guidelines
(P.15)