Post #2377948

> In Canada, The United States, and Mexico, the advertised octane rating is the average of the RON and the MON, called the Anti-Knock Index (AKI). It is often written on pumps as (R+M)/2. AKI is also sometimes called PON (Pump Octane Number). >Because of the 8 to 12 octane number difference between RON and MON noted above, the AKI shown in Canada and the United States is 4 to 6 octane numbers lower than elsewhere in the world for the same fuel. There's a table in the wiki article that shows the equivalence of different systems https://en.wikipedia.org/wiki/Octane_rating