Might just be how long the fuel tank takes to blend.How long would it typically take the ECU to adjust for an ~E20-25 blend coming from E10? I've noticed that if I add a couple gallons of E85, after ~5 mi, the car feels slightly down on power. STFT's are slightly higher. But then after a few more miles of driving or some harder acceleration, the STFT numbers come down, and there's noticeably more power. It would seem that the ECU is pulling back on the power a bit when the E-blend initially hits. I'm wondering what the normal time is for the ECU to adjust for fueling changes.