Diesel Prices Hit All-Time High as Iran War Squeezes Fuel Supply

The national average price of diesel fuel climbed to $5.85 a gallon on Friday, according to AAA's daily fuel price survey, the highest level the auto club has ever recorded and a fresh sign of strain from the six-month conflict between the United States and Iran. The figure edged past the prior all-time high of roughly $5.82 a gallon set in mid-2022, after Russia's invasion of Ukraine disrupted global energy markets. By Saturday morning, AAA's real-time tracker showed the average had climbed further, to just under $5.89 a gallon, up from about $5.29 a month earlier and roughly $3.70 a year ago.

Analysts trace the run-up to disruptions in shipping through the Strait of Hormuz, the narrow Persian Gulf waterway that carries a large share of the world's crude exports, along with Russia's decision to halt diesel exports and strikes that have damaged refining capacity in the Middle East. Domestic refiners have pushed output to roughly 97% of capacity to offset the shortfall, according to trade reporting, but supplies have remained tight. GasBuddy, a separate price-tracking service, confirmed diesel's new record in a Friday release, noting the increase has outpaced the smaller rise in regular gasoline, which AAA put at $4.15 a gallon.

Diesel powers the trucks, trains and farm equipment that move most of the country's freight and food, so the increase is expected to ripple through consumer prices. The Senate's Joint Economic Committee Democratic staff reported that American farmers spent roughly $1.4 billion more on diesel during this spring's planting season than a year earlier, a 63% increase that left some growers paying up to $1,500 more to fill an onsite fuel tank. The fuel also powers roughly 500,000 school buses nationwide and the long-haul trucking fleets that carry groceries, building materials and manufactured goods, meaning higher diesel costs tend to filter into retail prices with a lag of weeks or months.

Arizona Democratic Sen. Mark Kelly, who this week also joined 23 other senators in a letter pressing the administration over its decision to ease sanctions on Russian and Iranian oil exports, tied Friday's price spike directly to the war in a separate Thursday statement.

"Diesel prices have skyrocketed since Trump started his war with Iran. Diesel fuels our supply chains and powers our farms and food production. Even if you don't use diesel, those higher costs get passed on to you, making the food on your table more expensive," Kelly said.

The federal Energy Information Administration's weekly diesel survey, which uses a different sampling method than AAA's daily tracker, has likewise shown prices running well above year-ago levels in recent weeks, reinforcing that the increase is not confined to a single data source. Brent crude, the international oil benchmark, has traded above $95 a barrel in recent sessions, up from roughly $70 before the conflict began in the spring, according to NBC News reporting on the broader market pressures.

The White House has said the administration is working with oil companies to expand domestic refining capacity in response to the pump-price increases, and President Trump met with refinery executives in late August to discuss the issue. No timeline for relief has been announced, and analysts have cautioned that any capacity additions would take months to translate into lower prices at the pump. Congress remains divided over how to respond: Democrats on the Joint Economic Committee are pressing for a review of the administration's decision to ease sanctions on Russian and Iranian oil exports, while the White House has pointed to its refining push as its primary lever. With no resolution to the Iran conflict in sight and the Strait of Hormuz shipping lanes still constrained, traders and fuel retailers said they expect diesel prices to remain elevated, and potentially climb further, in the near term.