“Testing Methods:
The rest of the world, including Russia, primarily uses the Research Octane Number (RON), which is a single measure of a fuel's anti-knock properties.
US Method:
The United States uses the Anti-Knock Index (AKI)(or (R+M)/2), which is the average of the RON and the Motor Octane Number (MON).
Conversion:
Since MON is always lower than RON, the AKI is typically 4-6 points lower than the RON for the same fuel.
How A-76 compares
The number 76 in A-76 refers to the MON.
Since A-76 is defined by a single number (MON), this is the equivalent of the other number found on Russian fuel pumps.
Given that a fuel with a 92 RON in Russia is about an 88.5 AKI in the US, a Russian A-76 fuel would be roughly equivalent to the 85 AKI (or lower) range, fitting into the lowest tier of US gasoline grades.”
Comment: if a 92 Russian RON classification is closer to 88.5 US AKI octane rating, then a 72 Russian RON classification would be closer to a 64 US octane rating. Yikes!
That also means the Russian 95 gas is closer to 90 octane US.