Yeah Hi NTL
The ST220 will run with the 95 octane but the 98 octane is definitely better for the fuel economy because the whole engine management has been programmed really for 98 "Super". Depending on calibration of PCM your Ford Dealer can reprograme PCM and can chose which octane level you want to drive with. Not to mention the slight increase of HP you get with the 98 octane but better reaction and take on when you press the gas pedal. You'd only notice the slight differences if you were driving before on 95 and switched to 98..... if you really knew your car. You can drive with the 95, no problem but in the long run, depending on how you drive and if you want to keep the car for a long while, if you want to save your Engines Catalyst Converters I would go for the 98 octane.
It's not like the Focus RS that needs ONLY 98 octane!! Your choice really. Oh yeah we are in EUROPE we got 98 and 95 octane unleaded lol
~~~rabimec~~~