Fuel is fuel, all you need is any old 95 ron in a Miggy.
It's only a mig - not a formula one car 
The only benefit to the "premuim" fuels, is the additives that can clean the fuel system etc.... but you only need it once in a while, not all the time.
And car is a car?

There are big differences in the premium fuels, and can make a considerable difference. Filling up with BP Ultimate over regular BP is only about £2 more.
For the last year i have been running my 2.2 on BP standard fuel, occasionally using Ultimate, its much quieter and smoother on BP fuel, and the Ultimate stuff does add a noticeable improvement.
mpg is better driven normally
i found high revs - 4k+ there is more pull
smoother burn
Usually when ever i do a road trip i fill up with Ultimate, i need all the bhp i can get in a 2.2

That said i did average 34.6 mpg to York, fully loaded with friend & cruised at 80+