Originally Posted by C_Plunkett
In the US, the octane rating is the average of two tests, the research and motoring tests. That's why the octane rating on the gas pump will say (R+M)/2. The UK octane rating is only the research number (RON), so it will be a higher number for the same fuel in the US.
This is true! usa and uk are different. Here our 95, 98, 102, ect. are race only fuels. the highest at regular stations are 93, 94.