MrsMac and I did a bit of driving over this past Holiday weekend.
I can report that gas (petrol) in Pennsylvania ranged from $3.17 to $3.27 a gallon 87-octaine, self serve.
Diesel ranged from $3.59 to $3.87 a gallon.
The farther you got away from major metropolitan areas, prices tended to be at the lower end of the above scales.