Maybe - i put BP 93 in it with a bottle of outlaw octane booster and it ran like it was on Crack AND Meth! I was like - where was all this get up and go before.... I actually had to experiment to see if i was just loosing it so the next fill up i used just premium and the performance went back to normal after about 40 miles. When that was done I did it again and the crack head rush of performance came back. Maybe it's because Japan has different fuel (higher RON) than us and the car "knows" this.