Frantz

I will start by saying I have no intention of ever running 87 in my car, I ask to better understand the system and how it works.
The 2010 stock changes its tune slightly based on what kind of fuel you run from what i've read... Does an aftermarket tune override this whole system or does it just replace the higher tune?

Nuke

That's a great question for the guys at Brenspeed but since a custom tune does more than just make a minor adjustment for octane like the '10 stock tune does, I'd suspect that the custom tunes are designed to run on a '10 like it does on an '05 thru '09; it's designed to run on the octane it's written for and probably won't adjust for higher octanes.

BTW, why do you say you'll never run 87 octane? An 87 custom tune will kick *** over your '10s stock tune with 93 octane.