Record Diesel Prices Hit Trucks and Winter Oil Tanks

The U.S. average price of diesel stood at $6.43 a gallon on Friday, Sept. 18, a record in GasBuddy’s daily survey. Regular gasoline was $4.47, which is $1.96 cheaper on the same reading and $1.53 higher than when the Iran war began.

Most cars never buy a gallon of it. Trucks, combines, and oil-heat tanks do, and they are filling up just as fall harvest and the first heating-oil deliveries overlap.

A $6.43 Average, and $8 Pumps in California

GasBuddy’s Friday print is a live station average. Freight contracts still lean on the U.S. Energy Information Administration’s Monday survey, which put national weekly diesel at $6.285 for the week of Sept. 14. That weekly figure broke EIA’s old high of $5.810, set the week of June 20, 2022.

The same EIA table put California at $8.039. Some Los Angeles stations were already posting prices above $8 a gallon on Sept. 17. West Coast diesel as a whole was $7.250. The Gulf Coast, closest to U.S. refining, was still $6.027.

DIESEL BY REGION, WEEK OF SEPT. 14

EIA’s Sept. 7 reading of $5.967 had already topped the 2022 weekly record. The next week added another 31.8 cents. Brent crude was about $103 a barrel on Friday, down roughly 1.3%, and WTI was about $102, down 0.4%. Both stayed above $100 even as the day’s tape eased.

Spot Haulers Eat Costs That Contract Fleets Pass On

Diesel is how American freight moves. A truck that gets 6.5 miles a gallon now spends about 97 cents a mile on fuel at the EIA weekly average, up from about 59 cents at the $3.809 price logged the week of Feb. 23, just before the war. Over 100,000 miles, that gap is tens of thousands of dollars, and it shows up long before a grocery tag changes.

Large carriers recover a slice of that through fuel surcharges tied to the EIA index. A common broker formula, a $1.20 base and 6 miles a gallon, implies about $0.848 a mile at $6.285. Spot-market haulers, who take one-off loads without that clause, eat more of the pump price in cash.

You’ve got diesel prices almost at double what they were a year ago. Your large contract carriers are somewhat insulated from this discussion about diesel prices. I think it’s an important distinction. But your spot market carriers are getting crushed.

Dean Croke, principal analyst, DAT Freight & Analytics

J.B. Hunt told investors it expects third-quarter earnings to fall 5% to 10% from the prior quarter because of fuel. Intermodal units, boxes that ride trains for the long haul and trucks for the last miles, were up 4% in the first 36 weeks of the year, per the Association of American Railroads, while plain rail carloads rose 2.7%. Anne Reinke, president and CEO of the Intermodal Association of North America, said some owner-operators “shut down” when they cannot cover the fuel bill.

Carlos Vargas, owner of EDC Transportation in El Paso, said his weekly fuel bill jumped $50,000 about a month ago. Independent drivers have floated parking trucks on Oct. 1 until diesel falls to $2.50 a gallon. A strike like that would raise food prices faster than a slow surcharge, which is why the diesel shock is a freight story before it is a pump story.

WHO PAYS THE $6.43 GALLON

• Spot truckers: They buy retail diesel with limited power to add a fuel line to the rate confirmation.
• Harvest crews: Fall fieldwork lifts farm demand for the same distillate just as plants cut runs for maintenance.
• Oil-heat homes: About 4% of U.S. households still burn heating oil, most of them in the Northeast, and September is when tanks get filled.
• Shippers on contract: They do not skip the cost; they pay it later as a surcharge folded into freight rates.

Grocery shelves are the last stop on that chain. Food already rides diesel from the field to the warehouse to the store, so a record on-highway price is a delayed invoice for households that never own a diesel vehicle.

Why Diesel Costs More Than Regular Gasoline

Gasoline and diesel leave the same plants, but they are not the same market. Diesel shares a distillate stream with heating oil and jet fuel. When those three products compete for barrels, the on-highway price can run away from crude and from regular gas.

That is the spread on Friday: $6.43 diesel against $4.47 regular in GasBuddy’s survey. Gasoline is expensive, and it is still below its June 2022 weekly peak. Diesel is not. EIA’s 2026 annual diesel forecast is $5.07 a gallon, raised 4.4% in the September Short-Term Energy Outlook, with $4.40 in 2027. Those yearly averages only work if prices fall hard from here. They assume tanker traffic through the Strait of Hormuz returns to normal in the near term.

The war with Iran started on Feb. 28. Hormuz has been disrupted since that attack by the United States and Israel. Ukrainian strikes have also cut Russian refining, which used to send diesel into the Atlantic market. GasBuddy’s Patrick De Haan, head of petroleum analysis, said diesel rose 31.6 cents last week to $6.183 as of Sept. 14, with new hostilities in the Red Sea and a shutdown of Saudi Arabia’s East-West pipeline stacked on top of the strait.

EIA estimates U.S. diesel crack spreads, the gap between crude and diesel, will stay above $2 a gallon from August through November. That is the refiners’ side of the same barrel the truck is buying.

Distillate Stocks Sit 13.5% Below Last Year

U.S. distillate stocks, diesel plus heating oil in storage, were 107.9 million barrels in the week of Sept. 11. A year earlier they were 124.7 million, a 13.5% drop. East Coast stocks, the cushion for Northeast heat, fell to 19.318 million barrels in the week of Aug. 28, the lowest in EIA data going back to 1990. They had only recovered to 21.583 million by Sept. 11.

EIA’s September outlook still forecast distillate stocks below 100 million barrels in September, a level last seen in 2003, and below the 2021-2025 low through much of 2027. The Sept. 11 print had not broken 100 million yet. The forecast is the path EIA sees if exports stay heavy and fall maintenance cuts output.

Net exports of distillate have been above or near the five-year high in every month of 2026 since February, EIA said. Tight global supply “incentivizes U.S. exporters to increase distillate exports.” American plants are sending barrels abroad because the world price is high, and domestic tanks are the residual. Refinery utilization was 97.8% in the week ending Sept. 4.

THE DIESEL CALENDAR

1. June 20, 2022: EIA’s previous weekly high prints at $5.810 a gallon after Russia’s invasion of Ukraine.
2. Feb. 23, 2026: U.S. on-highway diesel averages $3.809, days before the Iran war.
3. Feb. 28, 2026: The United States and Israel attack Iran, and traffic through the Strait of Hormuz breaks down.
4. March 9, 2026: The weekly average jumps $0.962 to $4.859.
5. Sept. 7, 2026: EIA’s $5.967 reading sets a new weekly record.
6. Sept. 13, 2026: Exxon Mobil’s Joliet, Illinois, plant loses power and shuts down.
7. Sept. 14, 2026: EIA prints $6.285; GasBuddy’s daily national average is $6.183.
8. Sept. 18, 2026: GasBuddy’s daily national average reaches $6.43.

Fall is when U.S. plants usually cut distillate output for maintenance, and when farms raise diesel use for harvest. EIA warned that the two together, on already thin stocks, would lift both on-highway diesel and Northeast heating oil.

Exxon’s Joliet Refinery Is Still Dark

A local outage is now sitting on that global squeeze. Exxon Mobil’s Joliet refinery, a 275,000-barrel-a-day plant about 40 miles southwest of Chicago, went down after a power loss at about 3:30 p.m. CT on Sunday, Sept. 13. The company later said the fault was on ComEd’s lines into the site and that power had been restored. Production had not.

A Thursday filing said floodwater had overwhelmed a pump and that a containment boom was out for cleanup. Wood Mackenzie still listed the plant as offline on Sept. 17. IIR Energy had expected a return to normal service by the end of the week. The plant can make about 11 million gallons a day of gasoline and diesel for Illinois, Indiana, Iowa, Michigan, Ohio, Pennsylvania, and Wisconsin, according to Exxon’s own description of the site.

Patrick De Haan said Great Lakes spot diesel had become the highest in the country at $240 a barrel, a wholesale signal that Midwest racks were already tight before Joliet’s restart date slipped.

spot diesel prices in the Great Lakes are now the highest in the country… $240/bbl

— Patrick De Haan (@GasBuddyGuy) September 17, 2026

Gulf Coast barrels cannot fill a Midwest hole overnight. They have to move by pipeline, rail, or truck, and trucking is the mode whose fuel just set a record. Harvest states that draw diesel from Joliet’s system are the ones that feel an outage first.

Heating Oil Bills Jump 31.3% This Winter

Heating oil is chemically close to diesel, and it is sold from the same distillate pool. About 4% of U.S. households still use it, Mark Wolfe, executive director of the National Energy Assistance Directors Association, said, with most of that fuel burned in the Northeast. Those homes do not get a monthly utility bill for heat. A truck fills a tank, often 250 gallons at a time, and September and October are when many people place the first order.

WINTER HEAT BY FUEL

• Oil heat: NEADA forecasts a 31.3% jump in winter spend, to nearly $2,300 from mid-November through mid-March.
• All fuels: Average U.S. heating spend is put at $1,030, up $82, or 8.7%.
• Northeast: The regional average is $1,449, the highest in the country.
• Electric heat: Spend is projected to rise 9%, even if El Niño keeps the winter on the warmer side.

New York State Energy Research and Development Authority put the state’s average heating-oil price at $6.14 a gallon in the week of Sept. 14, up from $3.70 a year earlier. A Massachusetts survey found delivered heating oil at $5.98 on Sept. 14, up 62 cents from Aug. 24. EIA, which pauses weekly heating-oil collection in the warm months, projects retail heating oil at $5.66 a gallon in the fourth quarter and $4.94 in the first quarter of 2027, close to its on-highway diesel path of $5.55 and $4.93.

Wolfe said families are getting hit by gasoline and heating oil at the same time. EIA’s official Winter Fuels Outlook is due Oct. 6. Households that lock a price in September are buying the current distillate market, not the milder yearly average in the September STEO.

The $6.43 diesel average is already on the freight invoice. The heating-oil bill is the same barrel, arriving at the cellar tank before the first hard freeze.