U.S. Diesel Hits $6.16 While Grocery Prices Lag

U.S. diesel prices averaged $6.16 a gallon on Sept. 12, a record, as the Iran war kept fuel tight. AAA’s national print is up from $5.88 a week earlier and $3.70 a year earlier. Regular gasoline averaged $4.31, still below its June 2022 peak of $5.02.

August food at home prices were unchanged, even as diesel at the producer level jumped 24.1 percent in a single month. Freight contracts are where $6 diesel is landing first.

The National Average Hits $6.16

AAA posted a national diesel average of $6.16 on Sept. 12 and listed that figure as the highest it has ever recorded. The same table put Friday’s average at $6.06, the first close above $6. In a month, the national print has risen from $5.36, a 15 percent climb.

That $6.16 average is 66 percent above the $3.70 reading from a year earlier. Against the late-February mark of about $3.76, just before the United States and Israel attacked Iran, the rise is 64 percent. Most households do not buy diesel. They buy what diesel moves: groceries, parcels, furniture, and the rest of the freight that runs on No. 2.

SATURDAY’S AAA NATIONAL AVERAGES

The weekly government survey that trucking contracts actually use still sits a step behind the club’s daily pump watch. The U.S. Energy Information Administration put on-highway diesel at $5.967 a gallon for the week of Sept. 7, up $0.368 from $5.599 the week before. California led at $7.764. The Lower Atlantic region was the cheapest at $5.605, and the West Coast averaged $6.987.

In 2022 dollars adjusted for inflation, the old June 2022 peak of about $5.82 would be about $6.56 now, and the 2008 high of about $4.74 would be about $7.20. The Sept. 12 print is still a nominal record. It is also the number that surcharge tables, harvest trucks, and grocers will use next.

Grocery Aisles Are Still on Old Contracts

The Independent Grocers Alliance, which groups 7,500 supermarkets, puts fuel at roughly 15 to 30 percent of the total cost of food. Diesel runs tractors, boats, trains, and the refrigerated trucks that restock meat and produce several times a week. A shock that large should already be on the shelf. In the official price data, it is not.

The Bureau of Labor Statistics said the August consumer price index for food at home was flat on the month and up 2.2 percent from a year earlier. All food was up 0.1 percent on the month and 2.7 percent from a year earlier. Fruits and vegetables fell 0.4 percent in August and were up 3.2 percent year over year. Meats, poultry, fish, and eggs rose 0.1 percent on the month.

Wholesale prices told the other half of the story. In the diesel fuel jumped 24.1 percent in August, the Labor Department said, and that jump accounted for more than a third of the rise in final-demand goods. Final-demand foods rose 0.1 percent. Truck transportation of freight rose 2.0 percent. Prices for transportation and warehousing services rose 2.3 percent. Producer prices overall were up 0.4 percent on the month and 5.4 percent from a year earlier.

THE AUGUST LAG IN ONE SCREEN

• Diesel at wholesale: Producer prices for diesel fuel jumped 24.1 percent in August.
• Food at home: The grocery index was unchanged on the month and up 2.2 percent from a year earlier.
• Truck freight: Prices for truck transportation of freight rose 2.0 percent in August.
• All-items CPI: Consumer prices rose 0.4 percent in August and 3.4 percent from a year earlier.

David Ortega, a professor of food economics and policy at Michigan State University, has been describing that gap for weeks. Early costs sit inside existing freight contracts and retailer margins. The pass-through starts when those contracts are rewritten and fuel surcharges stick.

Early on, much of the cost increase gets absorbed along the supply chain through existing freight contracts and retailer margins. But as contracts reprice and fuel surcharges take hold, more of that cost makes its way to the grocery store.

David Ortega, professor of food economics and policy, Michigan State University

Patrick De Haan, a petroleum analyst at GasBuddy, has put a clock on the same handoff. If the spike lasts more than about six weeks, the contracts get rewritten. Diesel first crossed $6 on live GasBuddy data on Sept. 10. Six weeks from that print runs into late October, which is harvest season for a large share of U.S. farms.

How Fuel Surcharges Catch a $6 Gallon

Trucking does not wait for a grocery tag to move. Almost every U.S. fuel surcharge program keys off the EIA’s weekly on-highway diesel average, the figure the industry still calls the DOE index. The agency surveys about 350 retail stations each week. Brokers and carriers then plug that print into a table, usually with a lag of several days.

HOW THE SURCHARGE IS SET

• The index: Contracts cite the EIA weekly U.S. average, which was $5.967 for the week of Sept. 7.
• The lag: Parcel and LTL tables often take effect one business day to a week after the print, so this week’s pump jump hits invoices next week.
• The formula: A common per-mile table subtracts a low base price from the DOE print and divides by assumed miles per gallon.
• Who pays first: Owner-operators without a surcharge clause eat the diesel; shippers on indexed contracts pay it as a line item; grocers see it when those contracts roll.

Roadrunner Freight’s published table shows how fast that line item can swallow a rate. At the $5.967 index dated Sept. 7, the surcharge on LTL shipments under 20,000 pounds was 51.250 percent of linehaul, effective Sept. 9. On shipments over 20,000 pounds it was 102.500 percent. Fuel, on those heavy loads, now costs more than the haul itself.

That is why a $6 pump average can sit next to a quiet grocery index for a month and still be a live inflation problem. The first invoices belong to carriers and warehouses. The second round belongs to suppliers who mail surcharge letters. The third round is the shelf, and Ortega’s warning is that the third round has not fully started.

FedEx Ground Moves to a 28% Surcharge

Parcel carriers are already collecting. FedEx said it is lifting its Ground surcharge to 28 percent for Sept. 14 through Sept. 20, based on the Sept. 7 diesel print. The prior week, keyed to the Aug. 31 print of $5.599, was 27.00 percent. The company’s own table now steps 0.25 percentage points for every 9 cents of diesel once the fuel is at or above $4.99 a gallon.

FedEx states the lag in plain language: there is a delay between the fuel-price index and the surcharge. If the next EIA print, due Sept. 15, follows AAA’s $6.16 daily average, the Ground table’s $6.16 to $6.25 band would take the surcharge to 28.75 percent. That is arithmetic on the published bands, not a new FedEx notice.

WHAT SHIPPERS ARE PAYING NOW

United Parcel Service told investors its fuel costs rose 60.4 percent in the second quarter and that surcharges kept the hit off the bottom line, CFO Brian Dykes said. Amazon has used the 3.5 percent Fulfillment by Amazon surcharge, in place since April, to offset both diesel and tighter truck capacity, CFO Brian Olsavsky said. The Postal Service is the outlier: a flat 8 percent fuel surcharge on Priority Mail, Ground Advantage, and related services from April 26, 2026, through Jan. 17, 2027, with no weekly float.

Net fuel surcharge per ground parcel was already up 40 percent year over year in the second quarter on the TD Cowen/AFS Freight Index, which tied the rise to the Iran war and Strait of Hormuz disruptions. Holiday peak fees from the same four carriers start as early as late September. Those charges stack on top of the diesel tables, they do not replace them.

A Three-Decade Low in Saudi Supply

The reason the tables keep ratcheting is not a one-week refinery outage. The International Energy Agency’s September Oil Market Report said global oil production fell 1.6 million barrels a day in August to 100.1 million, with more than 10 million barrels a day of Gulf output still shut in. World supply is now seen averaging 100.7 million barrels a day in 2026, down 5.7 million from a year earlier, with a full Gulf recovery deferred until 2027.

IEA put Saudi crude supply at 5.97 million barrels a day in August, down from 8.24 million in July. The kingdom told OPEC it produced 6.238 million barrels a day, the lowest since 1990, and supplied 7.122 million by drawing stocks. Houthi-linked attacks on ships in the Bab el-Mandeb, on the Jazan refinery, and near Yanbu, plus drone strikes on the Abqaiq processing site, are the disruptions the agency cites.

FROM THE FIRST STRIKES TO THE $6 PRINT

1. Late February 2026: The United States and Israel attack Iran. AAA’s national diesel average is about $3.76 a gallon.
2. April 2026: Amazon adds a 3.5 percent fuel and logistics surcharge on some FBA services. USPS later locks in a flat 8 percent fuel fee through January 2027.
3. August 2026: Saudi supply collapses in the IEA’s books. Producer prices for diesel jump 24.1 percent. Observed global oil stocks fall another 95 million barrels.
4. Sept. 7, 2026: The EIA weekly diesel index prints $5.967, the number FedEx and LTL tables will bill against.
5. Sept. 10-12, 2026: GasBuddy then AAA take the national retail average through $6, with Saturday’s AAA print at $6.16.

Jim Burkhard, vice president and global head of crude oil research at S&P Global Energy, said the market is adjusting to a new normal, not returning to calm, and that Middle East crude output is not projected back to prewar levels by the end of 2027. Friday’s session left Brent at $104.61 a barrel and West Texas Intermediate at $100.05. IEA said ICE Brent had traded near $105 as it went to press, up $21 since the start of August and 45 percent above prewar levels. North Sea Dated, the physical benchmark, averaged $91 in August and surged to $113.48 on Sept. 9.

Why Gulf Diesel Exports Are a Quarter of Normal

Crude is the input. Diesel is the shortage. IEA’s September report, in a section it labeled a diesel squeeze, said U.S. diesel and gasoil prices surpassed $200 a barrel in early September, 94 percent above prewar levels, with Europe and Asia close behind. Refinery margins in the Atlantic Basin hit records on those diesel cracks. Singapore margins were weighed down by surging freight rates.

Total oil exports from Gulf countries in August were about 13 million barrels a day, nearly half their prewar level. Refined product and LPG exports were down nearly 60 percent, or 3.7 million barrels a day, from February. Net Gulf diesel exports at a quarter of the old pace averaged 390,000 barrels a day in August. Add Russia, where Ukrainian strikes have nearly halted product exports, and combined Gulf and Russian net diesel and gasoil exports were 1.6 million barrels a day lower than in February, when those two sources made up almost 45 percent of global seaborne diesel trade.

World oil demand is now forecast to fall 2.5 million barrels a day in 2026, a cut of 940,000 barrels a day from the August report, with the losses concentrated in middle distillates and petrochemical feedstocks, especially in Asia. IEA still sees demand recovering by 2.6 million barrels a day in 2027. Production is seen rebounding by 8 million barrels a day that year. Until then, the buffer is shrinking. Global observed stocks have fallen 507 million barrels since February, an average draw of 2.8 million barrels a day, including 95 million barrels in August alone.

President Donald Trump has said oil prices likely will not come down until after November’s midterm elections. The IEA’s calendar is longer than that campaign. A deferred Gulf recovery into 2027 means the DOE index that FedEx, UPS, and grocery freight use can stay elevated through a full harvest, a holiday shipping peak, and the next round of annual food contracts.

Harvest Trucks Will Pay Before Shoppers Do

Fall fieldwork is weeks away, and farm equipment burns the same fuel as the trucks that will haul the crop. A $6.16 national average is already a harvest input, even if the cereal aisle has not moved. Refrigerated produce and seafood will show it sooner than canned goods, because those loads run constantly and the reefer unit burns extra diesel. Locally grown items and goods still sitting on old freight contracts will show it later.

De Haan’s Sept. 10 note is the cleanest statement of the mechanism. The record is not a gasoline-story inconvenience for pickup trucks. It is the cost of moving the rest of the economy, posted in public, with the grocery index still lagging by design of the contracts.

HISTORY: diesel has crossed $6/gal nationally for the first time ever, according to live GasBuddy data. every truck, every delivery, every package, every grocery run just got more expensive. the cost of moving everything in america just hit a record. Statement⬇️ (9/10/26, 3p CT) pic.twitter.com/zijqu6vD9i

— Patrick De Haan (@GasBuddyGuy) September 10, 2026

The next EIA weekly print is due Sept. 15. That number, not Saturday’s AAA average, is what the 28 percent Ground surcharge and the 51 percent LTL tables will follow. If it tracks the pump, those percentages step higher again. Shoppers will see that as a 3.5 percent Amazon line, an 8 percent Postal Service fee, a higher UPS invoice, and, after the next round of supplier letters, a grocery ticket that finally matches the diesel that has already been expensive for months.