Not all Fords, Chveys, ect leave the factery in a perfect balance betwean performance and MPG, I find my 5.3 runs a lot better and gets more milage out of a tank than 87

 

Good info guys, thanks for it. He doesn't have tunes nor do I but we both told the family it's what we want for christmas haha. I don't know if I can wait though. I am in between duty stations so we will see what happens when I get there. The main reason I asked is because he was telling me I would do better if I put the higher octane in for the 1600 mile trip I am going to start on friday. Groton ct. to panama city fl. I told him I don't see any point to the extra money I don't get any gains from it. Again thanks for the info. And as to one of the comments about quality fuel... always! I don't go for the station thats the cheapest I try to stick with shell or sunoco. might be 3-5 cents more but its worth in imo.

 

I agree that higher octane alone does nothing for added performance.

Higher octane DOES allow you to run more spark advance without introducing detonation. This in turn does add a little power.

Running a little more spark advance usually equals a tad more power.

So, the only theroy that I think holds water as far as 'higher octane = more power' is in engine control systems that incorporate a knock sensor. A knock sensor usually works in conjunction with spark advance. The computer will keep adding advance (to a certain degree, a lot of factors come into play) until the knock sensor indicates detonation, and then the computer backs off advance, always seeking the perfect threshold of adding advance right up to the point of detonation (to a certain degree, a lot of factors come into play), and then backing it off.

In a system like this it is feasable that running higher octane actually may produce mild increase in power (although probably barely measurable) simply by allowing the computer to advance the spark a little more than it could on 87 octane.