Regular is fine. The CPU automatically adjusts to fuel in system. As far as performance, I don't notice a thing. Its an SAV not an M car. I have owned German cars (Audi/BMW) since 1988 and have always run regular with no problems. My wife's last Audi ran on regular for 10 years.
However, I must confess I do run premium in my 97 M3 & R 1150 RT. I
