Diesel refining margins hit record $100+ per barrel amid global supply crunch

U.S. diesel refining margins, measured by the diesel crack spread, surged past $100 per barrel in mid-August 2026, shattering previous records and underscoring a deepening global fuel crisis. The benchmark spread, which tracks the profit refiners earn turning crude into diesel, briefly exceeded $102 per barrel before easing to triple digits on August 18. It had never previously topped $89 per barrel, with the prior record set in October 2022 during the early stages of the Russia-Ukraine war. The latest spike reflects a confluence of disruptions: lost crude supplies from the U.S.-Iran war, export restrictions following drone attacks on Russian refineries, and broader infrastructure turmoil across key producing regions. Attacks on Libyan oil facilities and Houthi rebel strikes in Saudi Arabia have compounded tightness in global fuel markets. U.S. diesel exports, already at historic highs, are partially offsetting lost Russian volumes, but domestic inventories have fallen to their lowest levels for late August since 1996. High refining margins are encouraging companies to delay scheduled maintenance, raising the risk of unplanned outages that could further constrict supply and drive prices even higher. Analysts warn that retail diesel prices—already elevated since the outbreak of the U.S.-Iran conflict—could climb further as winter approaches, threatening higher heating costs and renewed inflationary pressures.