The Liberty Daily 
(The Daily Caller)—Diesel prices in the U.S. climbed to a record high Friday as the war in Iran and disruptions to global refining capacity tightened fuel supplies.
The national average for diesel reached $5.85 per gallon Friday, according to AAA, surpassing the previous national record set in 2022 during the global energy crunch that followed Russia’s invasion of Ukraine during the presidency of Joe Biden. The national average for diesel prices was $3.72 in February, the month the Iran war began, per the Bureau of Transportation Statistics.
The average US diesel price climbed above $5 per gallon in spring 2022 — following the escalation of the Ukraine war — and reached a peak of roughly $5.81 per gallon during the week of June 20, 2022, according to Energy Information Administration (EIA) data. Still, this was four cents lower than the new high recorded under the second Trump administration.
Gasoline prices have also increased sharply, with the national average reaching roughly $4.15 per gallon Friday, according to the American Automobile Association (AAA). The increase in diesel has coincided with elevated crude oil prices. Brent crude, the international oil benchmark, traded around $96 per barrel Friday as disruptions to global energy supplies continued to pressure markets, according to the AAA.
Most products consumed in the U.S. are transported by trucks and trains with diesel engines, while diesel also powers most farming and construction equipment, according to The U.S. Energy Information Administration. Higher diesel prices can therefore raise the cost of transporting goods and operating businesses.
Diesel averaged roughly $2.70 per gallon around the time Biden took office in January 2021 before steadily climbing throughout his first year. Prices accelerated in early 2022, rising from about $3.61 per gallon at the beginning of January to more than $5 per gallon by March and remaining elevated through much of the year, according to EIA historical data.
In May 2022, diesel prices reached a then-record $5.56 per gallon as Americans grappled with soaring fuel costs. By June, the national average had climbed even higher, reaching roughly $5.78 per gallon, the Daily Caller News Foundation reported at the time citing AAA data.
Prices eventually retreated from those record levels. Diesel fell below $4 per gallon during portions of 2023 and averaged about $3.76 per gallon in 2024, Biden’s final full calendar year in office, according to EIA data.
Energy markets have faced significant disruptions since the United States and Israel began attacking Iran on Feb. 28. The Strait of Hormuz, located between Iran and the Arabian peninsula, is among the world’s most important energy transit routes.
Approximately 20% of global petroleum liquids consumption passed through the Strait of Hormuz during the first half of 2025, according to the EIA. The agency estimated that 20.9 million barrels per day moved through the waterway during that period and noted that existing alternative routes could handle only a portion of those flows if the strait were closed.
The conflict has also affected the infrastructure needed to turn crude oil into usable fuels. A major Saudi refinery shut down following a drone strike early in the conflict, contributing to pressure on supplies of diesel and other refined petroleum products.
Global refined fuel supplies are also facing pressure from the war between Russia and Ukraine. Ukrainian attacks have damaged Russian refining infrastructure, while Russia has moved to restrict refined-fuel exports through the end of September.
American refiners have increased production as supplies abroad remain constrained. The difference between the price of crude oil and the petroleum products produced from it, commonly known as the “crack spread,” has widened as refined fuel prices have climbed, according to the EIA.
