In france the gallon on ron 98 would be $6 the gallon !
It's 1,35 euros by litter.

And I use Ron 98 or ron 95 depending on the stations...

Knowing that the crossfire can run on Ron 91 (Meaning that it can't run on Ron below 91 but easily on more than ron 91) because the lower the ron is, the more easily it explodes with low compression (meaning it can self ignite before the piston went all the way up) The higher the octane is the more compression ratio is required for self ignition.
(But, even with that, it's not easy to self ignite petrol, that is why petrol engine needs spark plugs)...