U.S. Diesel Averages $6.529 a Gallon in EIA's Sept. 21 Survey; USDA Raises 2026 Farm Fuel Forecast to $21.6 Billion

The Fuel Bill No Farmer Can Pass Along

A South Dakota grower running one combine at harvest now expects to spend up to $1,500 a day just to keep it fueled — double what it cost a year ago^[3]. That's not a rumor from the field. It matches what the government's own numbers say is happening nationwide.

The Energy Information Administration's weekly survey put the U.S. average price of on-highway diesel at $6.529 a gallon for the week of September 21, 2026^[1][2]. That's up from $5.599 just three weeks earlier, on September 1, and more than $2.75 above where it stood a year ago, at $3.74^[1][3]. The EIA's price series isn't adjusted for inflation, so "record" here means record in today's dollars, not necessarily an all-time high once you account for past inflation. Either way, it's the number farmers are staring at while combines run.

A Bill That Arrived at the Worst Possible Time

Corn and soybean harvest is underway right now, and harvest runs on diesel — combines, grain dryers, the trucks hauling grain to the elevator. On September 2, the U.S. Department of Agriculture raised its forecast for 2026 farm fuel and oil spending to $21.6 billion, a 28.8% jump of roughly $4.8 billion from the year before^[4][5]. That sits inside a broader forecast of $492.8 billion in total farm production expenses for the year, $21.2 billion higher than 2025 and $15.1 billion above what USDA predicted back in February^[4][5].

Purdue University economist Michael Langemeier estimates the fuel bill alone is running $11 more per acre for corn and $7 more per acre for soybeans than last year^[3]. On a 1,000-acre corn farm, that's about $11,000 in extra fuel costs before anything else is added in^[3][22]. The American Farm Bureau Federation, the country's largest farm lobby, says no major row crop is on pace to clear breakeven for the 2026-27 marketing year^[6]. USDA still projects net farm income at $158.4 billion for 2026, but that's down $4.3 billion, or 2.6%, from 2025 — and down 5.5% once inflation is factored in^[4][5].

Here's the part that makes this squeeze different from an ordinary bad year: farmers can't pass the cost along. Grain prices are set on global exchanges, not negotiated field by field. A trucking company facing high fuel costs can add a surcharge to a shipment. A farmer selling corn at the going market rate cannot. Every extra dollar spent on diesel comes straight out of the farmer's own margin, which is exactly why AFBF says the math isn't closing this year^[6].

Where the Squeeze Is Actually Coming From

To understand why diesel is spiking even as crude oil hasn't spiked nearly as much, you need one number: the crack spread. That's the gap between what a refinery pays for crude oil and what it can sell the finished diesel for — essentially the refiner's profit margin per barrel. On September 3, 2026, the U.S. diesel crack spread hit an intraday record of $108.02 a barrel^[13]. Since a barrel holds 42 gallons, that gap alone works out to about $2.57 of the price at the pump. In plain terms: the shortage isn't crude, it's refineries and finished fuel.

Three things are choking that refining capacity at once. Ukrainian drone strikes have knocked out close to a quarter of Russia's refining capacity, and Moscow has extended its own fuel export ban through the end of 2026^[12]. Houthi forces have struck tankers carrying Saudi crude through the Red Sea, after Saudi Arabia rerouted exports that way^[14][15]. And the war involving the U.S., Israel and Iran has disrupted flows through the Strait of Hormuz^[11][20]. Analysts estimate roughly 1.5 million barrels a day of diesel supply is off the world market as a result^[13].

Making things worse, the cushion that normally absorbs shocks like these is gone. Distillate inventories held by refiners, distributors and retailers fell to about 103 million barrels by late August — the lowest level for that point in the year since 1951^[13]. With no stockpile to draw down, any new disruption shows up at the pump almost immediately.

Washington's Fix, and Why Refiners Say It Would Backfire

On September 22, speaking at the United Nations General Assembly, President Trump said he's open to restricting U.S. diesel exports to bring prices down at home^[8][9][23]. Treasury Secretary Scott Bessent said the administration is studying whether a full or partial export ban is feasible, describing it as a question of available refining capacity^[9][23]. Iowa Senator Chuck Grassley has been pushing harder, calling high diesel prices "KILLING FARMERS INCOME" and urging an outright export embargo^[3]. Republican Representative Tim Burchett has introduced a bill to do exactly that^[3][8].

The logic sounds simple: if American refineries are producing diesel, American farmers should get it before it goes overseas. But the American Petroleum Institute, the refining industry's main trade group, argues the mechanics work against that idea. Chief executive Mike Sommers says a ban would "make the problem worse, not better — for consumers, farmers and the broader US economy"^[8]. Gulf Coast refineries were built to run at high volumes and sell the surplus abroad; domestic demand alone doesn't absorb everything they produce. If refiners lose the ability to sell that export share, the industry's argument goes, some would cut how much crude they process altogether — shrinking total diesel output rather than growing what's available at home. Moving Gulf Coast fuel to the East Coast by pipeline and ship is also slow and limited, so buyers there who currently import from Europe could end up with less supply, not more. Reuters reported that analysts broadly agree an export ban could push U.S. prices down briefly, then raise them^[10].

Overseas buyers are watching closely, because they depend on the same barrels. Europe's refineries don't produce enough diesel to cover its own demand, so it leans heavily on U.S. Gulf Coast cargoes, especially now that Russian supply is sanctioned and under attack^[18]. Mexico is in a similar position^[19]. Energy economist Philip Verleger has said a U.S. export ban could push world diesel prices up by as much as 100%, because diesel demand barely drops even as prices climb — trucks and tractors still need to run regardless of cost^[18].

Same Facts, Different Villain

Everyone agrees on the number. What they disagree on is who's responsible for it, and that fight has become entangled with the calendar: the midterm elections are in November, and diesel touches freight costs, food prices and rural voters all at once^[16]. Transportation Secretary Sean Duffy said on Fox News that the price surge is largely outside the president's control, pointing to Ukrainian strikes on Russian refineries and Houthi attacks as the drivers^[12][14][17].

Critics of the administration see it differently. They argue the Hormuz disruption followed military action the U.S. and Israel chose to take against Iran, making the price spike a consequence of a policy decision rather than a random external shock^[17][20]. Common Dreams, a progressive outlet, reported that Republican operatives are privately worried the prices can't be explained away through messaging, citing internal GOP polling it did not publish^[17]. From that vantage point, the export-ban talk arriving weeks before the midterms looks like an attempt to visibly act on a price problem the administration itself helped create.

Coverage split along similar lines. Reuters and NPR largely stuck to farmer-focused reporting sourced tightly to EIA data and named economists^[3][7]. The Washington Times framed Trump as taking action to ease prices, attributing the causes mainly to Ukrainian strikes on Russian refineries "and other factors" — a phrasing that softens any mention of the U.S. role in the Iran conflict^[8]. CNN described the export-ban idea as a "sledgehammer" that could "boomerang" on the U.S., pairing Trump's name with both Iran and Russia in its own framing^[11]. The National, an Abu Dhabi-based outlet, led with the conclusion that a ban would worsen the global crisis, centering importers' exposure over farmers' relief^[18]. Al Jazeera filed its coverage of Houthi tanker attacks under a "US-Israel war on Iran" category, framing the shipping strikes as part of an American-linked conflict rather than a separate campaign^[14].

What to Watch Next

Farm groups occupy a different position than either political camp: their message isn't about assigning blame, it's that the harvest bill is due now, regardless of who caused the price spike^[3][6]. That bill isn't going away on its own. Two numbers will tell you whether it's getting better or worse — the crack spread, which shows whether the squeeze is about refining capacity or crude oil, and USDA's next farm expense forecast, which will show whether that $21.6 billion estimate holds or climbs further^[4][13]. Neither an export ban nor anything else currently on the table restarts a bombed Russian refinery or reopens the Strait of Hormuz. Whatever Washington decides about where American diesel gets sold, the underlying supply shortage remains someone else's problem to fix.