[overdriv]

I can't seem to find any 93 octane fuel in the south western states, but most every fuel stop has had 91 octane fuel. Was wondering if any one has done testing of both to see what the LT1 gives up, if anything, when using 91 octane fuel?
Does the computer actually know when a fuel less than 93 is being used or does it only know there is more pre-ignition, knock?
The car seems to run the same and seems to get decent MPG, just wondering how much timing is being pulled out using 91 octane fuel.


It seems to be compensating for the thin air very well. Still runs like a beast when needed, or wanted.