its not ron is an international standard measurement the only country who doesn't apply to the standard is the burger munchers.
I read about the liberty B4 and they where talking about how Aus fuel(98@ pumps) was usable they could just knock a bit of timing of but Subaru decide to completely retune it to suit Aussie driving..they wanted it to run 95 as 98 is not available in someplaces they went for more torque and quicker spool..their liberty B4 runs 254 bhp but that's on 95 fuel.