US Diesel Prices Hit Record Above $6.50 Amid Global Supply Crunch

U.S. diesel prices reached a record high of $6.51 per gallon on September 21, 2026, according to AAA data, marking a significant surge driven by constrained global supply and tight domestic refining capacity. The national average has risen more than 87 cents in September alone, surpassing the previous peak set in 2022. The price spike is fueled by a combination of factors. Ongoing conflict involving Iran has disrupted shipments through the Strait of Hormuz, limiting crude oil availability for refineries. Simultaneously, Russia has imposed restrictions on diesel exports, which may extend through October as Ukrainian strikes continue to damage Russian refining infrastructure. These global pressures have coincided with a U.S. refining system operating at over 95% capacity for months, leaving little buffer to absorb additional supply shocks. The surge is having immediate economic consequences. According to FTR Transportation Intelligence, the increase has added roughly 37 to 44 cents per mile to truckers' costs. Spot market rates are passing these expenses to shippers quickly, while contract rates involve fuel surcharges billed later.