[AmishDude]

My guess is that the difference is that the prices are a reflection of the refiners having converted to the summertime blends.

[neb52]

No the gas used in metropolitan areas had to have the low emission additive taken out and replaced by Ethanol. The Additive was polluting the water table. Also Diesel had to have ultra-low Sulfur added as well. To do this the Refineries and Gas Stations had to clean out their tanks first causing a temporary pinch in the supply.