U.S. diesel prices first surpassed $5 a gallon in March, marking a significant milestone for fuel costs. The national average has climbed 33% since the start of the Iran War, with renewed fighting in the Persian Gulf disrupting supply chains and reduced refinery capacity limiting output.

Industry analysts point to geopolitical instability as the primary driver, as attacks on shipping lanes and oil infrastructure create uncertainty in global markets. Refinery maintenance schedules, delayed by labor shortages and regulatory hurdles, have further constrained domestic production.

Trucking fleets and agricultural operators face mounting operational expenses, with some independent operators reporting fuel costs consuming up to 40% of revenue. The Federal Energy Regulatory Commission has noted the trend but stopped short of intervention, citing market-based pricing mechanisms.