Welcome!! I was just down your way a couple of weeks ago. If you have petrol production experience, maybe you can put to rest the age old argument.....
Use Unleaded or Premium Unleaded?
I look at this argument differently than most but subjectively the octane rating of the fuel should match the knock capabilities of the otto-cycle engine compression.
Refineries use knock engines to test the fuels and fuel mixtures that are produced. Basically this is a variable compression engine that fuel is tested in (at variable compressions) and then compared to the same set of tests with a mixture of iso-octane and n-heptane. If the mixture/knock test is inline with 89% by volume iso-octane and 11% by volume n-heptane then the RON is 89 and so forth and so on. The gold standard in the 1920's was iso-octane with a rating of 100. N-heptane is/was assigned an octane rating of 0.
MON or aviation lean octane (motor octane #) is tested by a higher rpm motor and is tested through a variable ignition sequence which yields a substantially lower octane rating (hence the PON or pump octane # which in the US is the RON + MON/2 average).
Now having said all of that, one must consider the amount of reformate stock (unification reaction or smaller chains to make larger chains) in the gasoline versus the heavy cat crack stock in the gasoline (large carbon chains with tremendous heat/pressure/catalyst to crack the large chains into smaller more profitable ones). Reformate gasoline as well as
Hydrofluoric Alkylation can yield very high octane fuels but the amount of olefins (unsaturated carbon chains) yield very little parrafins (saturated hydrocarbons which = lubrication for the engine) and have to be blended to both increase the octane of lower octane feedstocks and allow the engine to run mostly on lubricating heavy cat crack gasoline.
What this all boils down to is getting fuel to burn (so that as much energy as is possible is transmitted to the piston making you smile) versus getting fuel to detonate (or predetonate/knock which most manufacturers are now using pezioelectric knock sensors to retard ignition timing which = less knock/less efficiency/less smiles).
Using lower than stated octane for compression can and will damage an engine. Using more than stated octane for compression will gain you no more power (but it will make your wallet lighter). Remember octane ratings are a measure of activation energy (needed to ignite) not the energy content of the fuel.
Typically high compression bikes require premium (compressions in the 11.0:1 and higher range and lower compression bikes require lower octane ratings (by virtue of the ideal gas law). So by answering the question, the lowest octane rating that doesnt make the engine knock is the most economical and needed fuel to purchase. Hope this helps!