Never mind found my own awser!
From the powerchipgold FAQ
For those considering running the Powerchip Gold 93 software, should they decide to run 91 octane for whatever reason, the ignition timing will automatically retarded, and the car will run the correct amount of ignition advance to suit.
Originally Posted by Trevize
While I would like to be able to run 93 oct all the time... I just don't see that happening in practice.
What would one expect with the PowerChipGold 93 on 91 oct gas?