i am not sure of what it is called, but my understanding of the process goes like this: alcohol vaporizes at a lower temperature than gasoline, so a burning puddle of alcohol burns faster and releases more heat *in a given time frame* than a burning puddle of gasoline, therefore it burns hotter. it also burns faster as the reaction rate of alcohols oxidation is faster than that of gasoline under identical conditions (that's the the splitting thing i mentioned earlier. if you really care you could double check that, i am not 100% sure if the claim is correct).
now the total energy released is more for gasoline (which is what it seems you are talking about), but the alcohol releases its energy faster under identical open air conditions.
i am also assuming units measured in volume, not weight, you appear to be talking about weight when making your assumptions.
and yes, all ethanol has the same energy density, i was talking about the various other forms of alcohol. drinking alcohols are also going to have different energy densities based on their percentage of alcohol of course.
in short, alcohol: lower energy density, releases it faster, so burns hotter for shorter.
gasoline: higher energy density, releases it slower so burns cooler for longer.
again, assuming a burning puddle on the ground. aerosolizing it is a different story entirely.
also, i may be completely wrong on this, i am doing it off the top of my head from high school chemistry. that was a while ago.