higher octane, car runs better?

[custom89stang]

my car is pretty stock (as u can tell from below) but for some reason it seems like when i put in 92 octane instead of 89 that my car runs a lot better, a lot smoother........ and i can tell it makes the throttle response btter

 

[JadeFalcon]

Stock 5.0 HO compression is 9.2:1, 87 octane is plenty for this, octane is simply for detonation, the quality of the fuel should be the same. It is possible that where you buy gas from has crappy 87 quality, and higher 92 quality. Which, is odd, since the longer a fuel sits, the worse it burns.. and one would assume higher octanes, being less sought after, would be more prone to degredation.

 

[87gtconv]

tell U this for some reason I get better gas mileage with 87 octane and timing at 13* but better performance with 91!!