The Octane rating at the pump is commonly shown (and identified) as (R+M)/2. R=Research Octane, M=Motor Octane. Because of this, it is usually 4-6 Octane points lower than in the rest of the world for the same fuel. If you are pumping 90 (R+M)/2, you are getting what MB would have called 94-96 octane in the 70s