Record U.S. Diesel Prices at $6.51 a Gallon Slam Transport Stocks, Threaten Inflation

U.S. diesel prices climbed to $6.51 a gallon on September 20, 2026, according to AAA, pushing transport stocks lower and sending fuel costs rippling through freight, food and consumer goods markets. The national average has risen more than 40 cents in the past week alone. J.B. Hunt Transport Services (JBHT) fell more than 13% on September 16 after finance chief Brad Delco warned at a Morgan Stanley conference that third-quarter earnings would drop 5% to 10% from the prior quarter due to fuel costs. He called the swings "some of the most radical and abnormal" ever seen and cited at least a $10 million headwind. The Dow Jones Transportation Average dropped more than 2% that day. The Energy Information Administration put the national on-highway diesel average at $6.285 a gallon as of September 14, up 32 cents week-over-week and $2.55 year-over-year. California's average was $8.039. The surge stems from U.S.-Iran conflict restricting Strait of Hormuz tanker traffic and Ukrainian drone strikes on Russian refining infrastructure, prompting Moscow to ban diesel exports.