Four days ago we wrote that $5.90 was the highest diesel price AAA had ever recorded. That record lasted until Friday morning. On September 11 the club's national average stood at $6.0556 a gallon, up 7.8 cents overnight, 20.6 cents in a week, 73.4 cents in a month and $2.35 from the same day last year. GasBuddy's live tracker had already crossed $6 on Thursday afternoon. No U.S. national diesel average has ever started with a six.
Three numbers, three days
The milestone arrived in the same order as the last one. GasBuddy, which averages live station reports, was first: its national figure passed $6.00 on Thursday, September 10, and Patrick De Haan, the company's head of petroleum analysis, posted photos of California stations whose price panels read $9.999 because the display physically cannot show a higher number. Five stations had hit that ceiling by his count, with the state average at $7.91. AAA, whose average is built from OPIS transaction data and updates once a day, printed $5.942 on Wednesday, $5.977 on Thursday and $6.056 on Friday, and now lists Friday's figure as the highest average in its records, ahead of the June 2022 peak of $5.82.
The third number is the one that decides how much of this you actually get paid back. The Energy Information Administration's weekly survey, the index written into most fuel surcharge schedules, is taken on Mondays. The latest reading, delayed a day by Labor Day and published Wednesday, is $5.967 for the week of September 7, a jump of 36.8 cents in one week and itself an all-time high for the series. The next reading comes out Monday, September 14, and until then a carrier on a standard EIA-indexed surcharge is being reimbursed at roughly nine cents a gallon below what the pump is charging today.
Why the refiners cannot catch up
Crude is expensive, but crude is not the story. Brent traded at $108 a barrel on Thursday; diesel futures in New York touched $5.03 a gallon the same day, the first time above $5 since April 2022 and the equivalent of about $210 a barrel. That gap between the raw material and the finished fuel is the crack spread, and Andrew King, director of the OOIDA Foundation, puts it at around $100 a barrel. His point is the one that matters for anyone waiting on relief: even if crude falls, diesel does not have to follow right away.
The reason is refining capacity, not oil. Ukrainian drone strikes have taken enough Russian refineries offline that Moscow has banned diesel exports through the end of September; exports through the Strait of Hormuz are recovering but remain well below pre-war levels. Vitol's chief executive told an industry conference in Singapore this week that lost fuel exports from the Middle East and from Russia now amount to about 2 million barrels a day each. U.S. refineries are running at close to 98 percent of capacity, according to King, and are exporting record volumes to fill the gap, which is why domestic inventories are not building the way they normally do before winter. EIA's September outlook expects U.S. distillate stocks to fall below 100 million barrels this month and to stay under the five-year low through much of 2027; OOIDA notes that would be the first time below that line since 2003. The same outlook puts the fourth-quarter average retail diesel price at $5.55, which would be a relief only by comparison with today.
What six dollars costs per mile
At 6.5 miles per gallon, Friday's price works out to 93.2 cents of fuel per mile. A year ago, at $3.71, the same truck burned 57 cents a mile; a month ago, at $5.32, it was 81.8 cents. For an owner-operator running 10,000 miles a month that is $9,316 in diesel this month against $5,708 last September, a difference of about $3,600 a month before any surcharge. A 250-gallon fill that cost $926 a year ago costs $1,514 today. Lewie Pugh, OOIDA's executive vice president, put the same math in plainer terms this week: every dollar diesel goes up costs a trucker more than $400 to fill the tank, and on contract freight the rates take time to catch up. Truckers feel it first.
The rest of the economy is starting to feel it too. The Labor Department reported Thursday that producer prices rose 0.4 percent in August, and that diesel alone, up 24.1 percent for the month, accounted for more than a third of the increase in goods prices. Economists at Capital Economics told CBS News that retailers have so far absorbed the cost under existing contracts, and De Haan's threshold for that to change is about six weeks: if $6 diesel lasts that long, large shippers renegotiating fuel clauses will pass it through to groceries, furniture and vehicle destination charges. Six weeks from Thursday is October 22.
Where the state tax holidays leave truckers
Indiana extended its gas tax suspension for a fifth time through October 5, but diesel is excluded and pays the full rate. Utah's 15 percent cut through year-end also leaves diesel out. Kentucky's 10-cent cut on both fuels expired June 30. In Pennsylvania, where the diesel tax is 74.1 cents a gallon, bills SB1265 and HB2396 would suspend it for 60 days and six months respectively, but both are still pending. As of today, no state is giving diesel a break.
Checklist
What to check this week
Pull your fuel surcharge schedule and find the index and the base price. If it is EIA-indexed, you are being paid on $5.967 until Monday's number lands; if it is on a monthly average, you are still being paid on August.
Check the mpg assumption in the schedule. A surcharge built on 6 mpg pays more per mile than one built on 7; at $6 diesel the gap between those two assumptions is about 11 cents a mile on a schedule with a $1.25 base price and 14 cents on one with no base.
On spot loads, quote the fuel line separately and date it. A rate agreed Monday at $5.85 is underwater by Friday.
Plan fuel stops by state, not by convenience. AAA's Friday table runs from $5.53 in Oklahoma and $5.58 in Texas to $7.00 in Washington and $7.91 in California; on a 250-gallon fill the spread between Oklahoma and California is about $600.
If you run California, fill before the state line. Five stations are already at $9.999, which is the display ceiling, not a price ceiling, and the state average is $7.91.
Watch October 22. That is six weeks from the day GasBuddy crossed $6, the point at which the analysts quoted here expect the surcharge fight to move from carriers to shippers and consumers.
Sources: AAA Fuel Prices national average and 'highest recorded average price' table, September 11, 2026; GasBuddy and Patrick De Haan (@GasBuddyGuy), September 10, 2026; U.S. Energy Information Administration, Gasoline and Diesel Fuel Update, data for September 7, 2026, and Short-Term Energy Outlook, September 2026; Bloomberg News via Transport Topics, 'Diesel futures top $5 a gallon for first time since 2022,' September 10, 2026; CBS News, 'Diesel prices near $6 a gallon,' September 10, 2026, including Bureau of Labor Statistics August Producer Price Index; Land Line, 'Fuel cost relief unlikely for some time' and 'Pain at the pump: These states are trying to offer a break,' September 9, 2026; FreightWaves, September 9, 2026.
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