isnt most if not all of these engines high compression,,, i would think 14 to 1 to 17 to 1 is high compression,,,but since these engines are alot smaller than there larger counterparts,,, they arent as sensitive,,,heck 17 to 1 or bit higher your into diesel territory,,,,,higher octane does help, runs smoother , burns better,, better throttle response,, and less chances of some detonation,,, melted piston and spark plug and engine failure,,,i have been breaking my engine in on premium,, but plan on stepping up to turbo blue, have a drag strip nearby and some local stations sell it out of the pump...