This may be helpful when talking about regional differences in fuel and engine tuning. Sometimes someone will pop in and say US fuel is of lower quality compared to EU. As always it's the details which matter
Agree but I've found that when it comes up they're actually talking about differences in octane.Quality of fuel has nothing to do with it's octane rating.
Yep. MON is always lower than RON, how much lower varies and is called "sensitivity".... I seem to recall that the nature of the fuel components(i.e. alkane, aromatic, alcohol, ether, etc) can change the relationship between ROM and MON. ...
True, MON is closer to a real-world result, measured at higher RPM and temperature. This is when pre-ignition is most likely, and when the engine actually needs the octane.... Both numbers certainly have their place, and there's no perfect way to categorize fuel, but to my mind the MON is more of a "real world" number given that, in general, engines don't vary their compression as in RON(I know VVT can change dynamic compression, but it's also a relatively recent development) but variable ignition timing has been used, well, since the beginning of practical gasoline engines.
Agreed... using the US AKI((R+M)/2) is probably the best balance of approaches, but I'm sure there are arguments for both. ...
Yep. MON is always lower than RON, how much lower varies and is called "sensitivity".