The price differential between diesel and gasoline should diminish over the next year or so. Prices are set by supply and demand, and while demand for gasoline in the U.S. has actually been dropping this year, the majority of diesel usage is less flexible than gasoline, e.g., while people can cut down on the use of their cars, over-the-road semis delivering goods is not discretionary.

Assuming this change in the ratio fo gasoline to diesel remains, the refineries will make some changes to their operations to get more diesel and less gasoline. Unfortunately, to change this ratio significantly is not easy for refineries, so it will take some time for (a) the refiners to believe this is a permanent change, and (b) make the modifications to their equipment.