The U.S. average retail price of diesel was $5.97 per gallon the week of September 7, 2026, up $2.25 from its February average of $3.72, before the disruption in the Strait of Hormuz began. Crude oil accounts for 68 cents of that increase. The refining margin — the gap between the wholesale price of diesel and the cost of the crude it is made from — accounts for $1.71. The world is short of refined diesel rather than crude oil. Russia, once Europe’s largest diesel supplier, has nearly stopped exporting refined products after Ukrainian attacks on its refineries and a...