We have ULP at 91, intermediate at 95, premium ULP at 98 & E85 for Flex-fuel engines, that's 107 octane.
Back in the 90s, in Europe the Ford Mondeo & Opel Vectra were competing for the same market share, both used the European base level fuel of 95 octane and the Mondeo offered better performance.
When they went on sale in Australia, only the Vectra was modified for 91 octane, meaning that, on the standard, base-level fuel, the Vectra outperformed the Mondeo. And there's usually 4c per litre price difference between 91 & 95-octane, unless you use 95-octane E10, which is a few cents per litre cheaper than the 91.