What I've read on the subject is that there are 2 oil refining methods used around the world. One produces among others more gasoline and the other more diesel fuel. Guess which one is used in the EU and which one in the US. You guessed it right I hope.
Add to that the recent Federal mandate to produce low sulfur diesel fuel and the resulting infrastructure upgrades cost, higher demand for it and the supply / demand works its magic.
That said any fuel in the US is still half price what it's in most EU countries. Fuels are heavily taxed in the EU, very little in the US, i.e. giving the EU countries more flexibility when it comes to shifting prices. Besides EU governments have historically interfere with the economy more than the US. When was the last time a major EU company went bust without being rescued by tax payers? Almost never happens there. Companies go out of business all the time here.