U.S. diesel prices reached a record national average of $6.05 a gallon on Friday, September 11, 2026, as the war with Iran disrupted global fuel flows. The average rose from $5.85 a week earlier and $3.70 at the same time last year, according to motor club AAA.
The increase is raising transportation costs across freight and delivery networks that carry everyday goods. Some businesses have already passed higher expenses to consumers through added fees on online orders and mailed packages, while further costs may take time to reach shoppers.
Perishable foods such as meat and produce face particularly immediate pressure because they must be transported and restocked frequently. Some are also harvested with diesel-powered farm equipment, adding another point at which higher fuel prices can affect costs. Regular gasoline also reached a U.S. average of $4.29 on Friday.
Diesel prices have climbed sharply since the U.S. and Israel launched their war against Iran in late February, when the national average was about $3.76 a gallon, according to AAA. Crude oil rose amid Middle East supply-chain disruptions, including a bottleneck affecting most tanker traffic through the Strait of Hormuz. After easing during hopes for peace earlier in the summer, oil resumed its climb as fighting escalated again.
Both Brent crude and U.S. crude exceeded $100 a barrel this week for the first time in months. Brent, the international benchmark, traded above $105 on Friday, compared with roughly $70 before the war. Crude oil is the principal ingredient in refined fuels including diesel and gasoline, tying pump prices closely to changes in the oil market.
Although the current diesel average is a nominal record, inflation-adjusted prices have been higher. Diesel reached about $4.74 a gallon before the 2008 financial crisis, equivalent to $7.20 in 2026, according to the latest government data. The previous nominal record of nearly $5.82 in 2022, reached months after Russia invaded Ukraine, would equal about $6.56 in 2026 after inflation.