Read the manual. It says about this.
It says something along the lines of you can run on 95 Ron fuel if performance fuel is not available. Don't rev above 3500rpm and don't put the engine under heavy load. Fill up with performance fuel as soon as possible.
Jez is an engine tuner mate.
I think what he means is that it knocks at low rpm mostly and not too bad at high rpm. The good thing is the 350z has a knock sensor/controller at low rpm.