I use Sunoco 94 thats the highest I can get in Pa. I talked with others on another site like this and they stated to stay away from aviation fuels because they are formulated for low RPM motors. I have a pilots certificate and flew single engine planes for 10yrs. As I recall the highest RPM I ran a plane was 2700. I can't put any truth to this as I have ran av gas in many different engines just because of it's stability.