As midnightsadie said, there is no reason for it other than what sellers want to charge. With all of the oil starting to flow in the US and we're now exporting refined gas and diesel to other countries so there's no reason for it other than the sellers can do what they want. Remember the last couple of years when refineries blew up in both Washington and California, they immediatly jacked up the fuel prices and said it was because of the resulting fuel shortage, but did you ever see a line backed up at a gas station because of the shortages? It was just the most current excuse to use.
Useing corn in the bio fuel not only raises the price of the fuel, but also the cost of the corn you eat and the price of meat because the cost of corn feed for the steers as gone up.
Bill
Nodwell RN110 out moose hunting. 4-53 Detroit, Clark 5 spd, 40" wide tracks, 10:00x20 tires, 16,000# capacity, 22,000# weight. You know the mud is getting deep when it's coming in the doors.