This isn't helpful at all, but here some price comparisons from the summer (June) high price season.
Yes, people were looking at me for taking pics of fuel prices...
Garmisch-Partenkirchen:
Panzendorf, Austria (near the Italian border):
Tosolano-Maderno, Italy (Gardone Riviera, Lago di Garda):
And finally,
TAX FREE FUEL from the Shell in Livigno, Italy (Lago di Livigno):
I also bought a 1 liter bottle of Jack Daniels from the Shell shop for 8€. :yikes:
The most expensive Shell "Super" Diesel (V-Power) that I found, was from Bologna, Italy... and I did not take a pic there - we were in a hurry to get to Venezia. Price was 1,67€/liter. I bought a full tank!

:rofl: