High Octane gas and performance tunes

[Alabama-man]

Having looked into getting a performance tune for my 2006 Sierra 4.8L, I found out that one tuner in particular offers up different levels of performance based on what octane of fuel used. In other words, if you use regular then performance gain is say 10HP (hypothetical) and if you use premium then performance gain is 20HP. Does anyone know how this works?

[redvett]

If your looking for fuel economy have a economy tune done and have it set for regular. Without raising the compression ratio will do little or nothing to improve your economy other than cost you more of gas and if your trying to save money thats not going to do it . Just slow down and drive less agressive.

[Chanks7]

When you are using higher octane fuel the computer can increase spark timing increasing horsepower, using 87 octane on the high octane setting will cause the engine to PING. On my mustang the easist 15hp I gained was increasing timing form 11 degrees to 15 degrees and running premium gas.