Why Diesel Prices Differ From Gasoline Prices
The price of crude oil is the main factor in the price of diesel fuel, and fluctuations in the crude oil market greatly influence changes in diesel prices. Short-run factors that can cause divergences from this correlation include: supply shortages resulting from refinery outages, transportation issues, adverse weather conditions, and pipeline problems.
Longer-term factors that have been tied to variations in gasoline versus diesel prices include the different seasonal price variations for the two fuels, and differing tax rates.
For more information, see "U.S. Gasoline and Distillate Fuels Update" below.