higher octane fuel is designed to be less volantile... people dont seem to understand that..
and that putting higher octane fuel in a car where it isnt req'd will often hurt performance... it doesnt help anything if the car doesnt need higher octane fuel.... except sometimes with older cars, they will start having knock issues. in this case often up grading the gas will stop and fix the issue.
other than that you are just wasting money.
basically as gas gets compressd it gets more volantile, well ur car has lower compression ratio, so its not getting the higher grade gas to the compressed point it needs for a clean and thourough burn from the spark plug.
so higher octane fuel is just requires more compression b4 it burns like normal fuel..
i tried explaning it in a way everyone could understand
you really want to put better gas in your car? find gas stations around you that have etanol free gas... sadly theres not one close to be.. but i guarntee if you use ethanol free gas, you will see better mgp... ethanol is screwing us royally. it adds cost by manufacturing it, thus offsetting the 10% less gas we are actually getting, and it doesnt burn as well as gasoline. so we are actually paying the same amount or more, for a lesser product!(we get robbed of power and mpg by ethanol)