The national average price of diesel in the United States hit a record high of $5.85 per gallon amid the war with Iran, according to data released on September 4, 2026, by the American Automobile Association (AAA). The figure surpasses the previous peak recorded in June 2022 after Russia invaded Ukraine, driving up transportation and production costs of many products, including groceries, ahead of the November congressional midterm elections.
Diesel and Gasoline Prices Reach Record Levels
The spike in fuel costs impacts a wide range of logistics sectors across the United States. Diesel is mostly refined from crude oil in the US and powers heavy machinery, buses, trains, and large trucks. According to the American Automobile Association, gasoline prices also climbed to $4.14 on Friday ahead of the Labor Day weekend, marking a record high for this time of year. Before the Trump administration joined Israel in starting the war on Iran, a gallon of gasoline was less than $3.
Public opinion polls have shown that the war with Iran remains unpopular with US voters, positioning the cost of living as a top electoral issue. The Republican Party pushes to retain control of both the US Senate and the US House of Representatives in November.
Strait of Hormuz Disruptions and Market Volatility
The energy crunch stems from disruptions in the Strait of Hormuz, a major artery for the global energy trade. Following opening US and Israeli strikes in February by the US and Israel, Tehran shut down the waterway, sending oil and gas prices soaring. Continued volatility in the strait has pushed crude oil prices in the $90 per barrel range, according to AAA reports.
Despite ongoing market turbulence, the administration of President Donald Trump maintains that the US military is now in control of the waterway. On Thursday, President Trump shared a social media post claiming that 18 million barrels of oil are passing through the strait daily, nearly the same amount as the pre-war levels. US Vice President JD Vance echoed this assessment to reporters, stating that Iran’s control over Hormuz is “effectively gone” and that oil and gas coming out of the strait is almost back to where it was before the conflict started.
Independent verification of these transit volumes remains challenging. Tankers crossing under US protection turn off their transponders to go undetected by Iranian forces. Meanwhile, Tehran insists that Hormuz is still under Tehran’s control, pointing to continued regional friction. Suspected Iranian strikes on ships in the strait have continued almost daily, including an attack earlier this week on a Saudi tanker that killed two sailors.
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