I figured this would be the best place to ask since you guys are all imside these ECU's and you really know whats going on.
I was wondering what octane fuel the stock volvo ecu is written for so I did some searching.
per owners manual " Volvo engines are designed for optimum performance on unleaded premium gasoline with an octane rating. AKI of 91, or above. AKI (ANTI KNOCK INDEX) is an average of the Research Octane Number, RON, and the Motor Octane Number, MON, (RON + MON/ 2). The minimum octane requirement is AKI 87 (RON 91)."
This is conflicting in itself and a crock of stuff. Your engine cant have "optimum performance" at 2 different octane levels, say 91 vs 94, is one or the other.