$6.00. Diesel has never cost this much as a national average per gallon (3.785 liters) in the USA. US President Donald Trump's war against Iran has caused fuel prices to rise rapidly. An overview of the implications for the United States.
Why is diesel so expensive anyway?
Basically, the energy crisis as a result of the continued disruption of oil trade through the Strait of Hormuz is contributing to the increase in prices. Due to the Iran war, hardly any crude oil from this region reaches the world market, and the tight supply leads to higher prices. On Thursday, the price of a barrel (159 liters) of North Sea Brent crude oil for delivery in November climbed to $108 for the first time since May after the war between the USA and Iran escalated militarily again.
In detail, the diesel price is made up of several components. According to the US Energy Information Administration (EIA), these are:
Cost of purchasing crude oil
Refinery operating costs
Sales, marketing and gas station costs
Taxes
The price of crude oil is the largest cost factor for diesel. Between 2004 and 2025, it accounted for about 51 percent of the average monthly retail price for diesel on U.S. highways, it said. At the same time, sales costs rose.
The fact that diesel has historically been more expensive than gasoline for years is due, among other things, to the fact that demand for diesel is greater, particularly in Europe, China, India and the United States, and the federal tax on diesel is higher than on gasoline. A large proportion of the car fleet runs on petrol, but almost all transport vehicles run on diesel.
How does this affect companies in the country?
Sectors that rely on diesel in particular have to shoulder the increased expenses. According to an analysis by the nonprofit American Transportation Research Institute (ATRI), fuel costs accounted for about a fifth of average operating costs in the trucking industry in 2025. Due to the ongoing escalation in the Middle East and the resulting energy crisis with higher prices, the share is likely to increase significantly.
The EIA also recently sharpened its diesel price forecasts. She now expects an average price this year of $5.07 per gallon, which is 4.4 percent more than estimated in August. For 2027, the experts assume that the price will then fall to $4.40 per gallon. Even that would still be 8.2 percent more than previously assumed. For comparison: in 2025 the average price was $3.66.
As a result, haulage companies, construction, agriculture and forestry as well as other industries that rely on diesel will only be able to partially offset their increased expenses. The rest is passed on to customers, which in plain language means price increases. Food, everyday items and other cargo are likely to be affected.
How does this affect the US population?
At first glance, the population is not affected by the increase in the price of diesel, as the motoring nation usually fills their vehicles with “regular”, i.e. petrol. And yet: The Iran war is also causing gasoline prices to skyrocket. On Thursday, fuel averaged $4,277. A year earlier, Americans had to pay $3.1938 per gallon.
Compared to Germany, refueling in the USA is still cheap. Converted to liters and euros, the current US gasoline price is around 97 cents and diesel is around 1.37 euros. According to ADAC information, the E10 variety recently cost an average of 2.259 euros per liter in Germany. Drivers had to pay 2,321 euros per liter for diesel.
In the USA, however, the consequences of high inflation, which is exacerbated by the energy crisis, are more serious. The inflation rate in the USA has been above the two percent target of the US Federal Reserve for more than five years.
When will fuel be cheaper again in the USA?
There is no immediate improvement in the situation in sight due to the deadlocked conflict between Washington and Tehran. Even Trump no longer believes that gasoline could become cheaper in the foreseeable future. "I think it's going to take a little longer than the midterms," he said when asked by reporters when gasoline would fall below $2 a gallon again. Months ago, the Republican claimed that prices would soon fall “like a stone”.
The fact that there is no end in sight is probably due to the fact that there are less than two months until the important parliamentary elections in his country. Sooner or later, Trump will have to decide whether he wants to support his party - or even can - or whether he wants to devote his attention to foreign policy.
The fuel prices that have been high for weeks are unlikely to cause much enthusiasm among voters, and his latest admission is unlikely to be of any help to the already low approval ratings for Trump and his policies.
