Hi i was wanting 2 know this.I have a 2003 st170 and ive been useing normal unleaded 95.Can i just switch 2 super unleaded or the unleaded 97 without any problems.I have been told the better the petrol it will save on parts espesilly the oxegen sensor.

 

Doubt it will run any different on premium fuel. Would have been designed for 95 ron. It just a normal car. Super unleaded on a sports car yes, but not a Focus.