U.S. national average diesel prices reached $6.28 per gallon in October 2026 following market disruptions caused by the war in Iran, down from a September 2026 peak of $6.52 per gallon.

The armed conflict between the United States and Iran and the political fight it set off at home, from strikes and the naval blockade around the Strait of Hormuz to negotiations over Iran's nuclear program. Debated through war powers, munitions stocks and household costs.