Does the CX-9 tune/ecu treat any octane below 93 as 87, or does it increase horsepower incrementally? Where I live I can get gas at 87, 89, 91, and 93. So can the ecu detect 89 and increase hp to, say, 234? And at 91 increase to 242? Or is it all or nothing, 93 = 250 and anything below = 227?