Diesel Hits a Record as U.S. Gas Prices Climb

AAA put regular gasoline at $4.44 a gallon on Sept. 17, up 16 cents from a week earlier. That print is $1.24 higher than a year ago.

Diesel, the fuel that moves trucks, set an all-time high of $6.40 the same day. The gasoline map is what voters see. The diesel record is how six months of the Iran war still shows up in freight and food.

A $4.44 Gallon, $1.24 Above Last Year

The motor club’s dashboard listed the national regular average at $4.4386 as of Sept. 17, which rounds to $4.44. A week earlier it was $4.28. A month earlier it was $4.06. A year earlier it was $3.20.

AAA’s Washington note framed that as a 16-cent weekly jump in regular gasoline and said crude was still averaging about $100 a barrel. West Texas Intermediate settled at $102.43 on Wednesday after a $3.40 drop, so the oil tape eased a little while the pump did not.

THE AAA NATIONAL PRINT

• Regular: $4.44 on Sept. 17, up 7 cents from Sept. 16 and 16 cents from a week earlier.
• This year’s gasoline high: $4.56 on May 21, which leaves the new print 12 cents short of that mark.
• All-time regular high: $5.01 on June 14, 2022, so today’s gallon is still 57 cents below the record.
• Year-ago gap: $1.24, from $3.20 on the same comparison in 2025.

The Energy Information Administration’s separate weekly survey, priced as of Sept. 14, put regular at $4.319, up 16.2 cents on the week and $1.151 from a year earlier. That weekly series lags the daily AAA print and should not be read as a second current price.

AAA also said gasoline demand rose from 8.55 million barrels a day to 8.79 million, while domestic supply ticked up from 206.9 million barrels to 207.7 million. Production rose from 9.3 million barrels a day to 9.6 million. U.S. crude stocks fell 0.6 million barrels to 423.4 million, 1 percent above the five-year average. The oil is there. The refined gallon still costs more.

Diesel Posted an All-Time High of $6.40

AAA’s diesel average on Sept. 17 was $6.3956, logged as the highest recorded national diesel average on that dashboard. A week earlier diesel was $5.98. A month earlier it was $5.45. A year earlier it was $3.71, which puts the new print $2.69 higher.

That is a 42-cent rise in seven days, more than twice the weekly move in regular gasoline. The EIA’s weekly on-highway series, again dated to Sept. 14, already showed a weekly diesel average of $6.285, up 31.8 cents from the prior week and $2.546 from a year earlier. California diesel in that survey was $8.039. The West Coast was $7.250. Even the Gulf Coast, usually the cheap pad, was $6.027.

REGULAR VS DIESEL ON SEPT. 17

Gasoline can dominate a midterm argument because almost every voter buys it. Diesel is the quieter bill. It fills the trucks that haul groceries, the tractors that cut harvests, and the vans that make last-mile drops. When that gallon sets a record, the next place it appears is a shipping surcharge, then a shelf tag.

Record diesel prices will impact every cargo, shipment, every delivery Americans are taking, and are likely to reignite inflation up and down the supply chain.

Patrick De Haan, head of petroleum analysis, GasBuddy

Public EV charging, for comparison, held at 42 cents a kilowatt-hour in the same AAA note. That option only helps the slice of miles already running on a plug. Most freight still burns diesel.

$6.08 in California, $3.92 in Indiana

AAA’s Sept. 17 state list still has the same shape it almost always does. California led at $6.08. Washington was $5.57, Hawaii $5.48, Nevada $5.19, Oregon $5.11, and Alaska $5.07. Idaho, Utah, Illinois, and Michigan rounded out the ten dearest markets, from $4.85 down to $4.75.

Indiana was cheapest at $3.92. Texas and Mississippi were $3.93. Louisiana was $3.97 and Alabama $3.99. Arkansas, Oklahoma, Tennessee, Kansas, and Georgia filled out the bottom ten, all between $4.03 and $4.08. The gap between California and Indiana was $2.16 a gallon.

Some of that spread is old plumbing. West Coast fuel has to meet a tighter blend, travel farther from Gulf Coast refineries, and clear higher state taxes. Gulf and Midwest pumps sit closer to the plants. The Iran war did not invent that map. It lifted the whole floor under it.

Illinois at $4.78 is the reminder that this is not only a coastal story. A high-tax Midwest state now sits in the national top ten, next to Idaho and Utah, while Texas, a producer state, still prints under $4.

The Midwest Took the Week’s Biggest Jumps

The weekly change, not the rank, is what moved inland. AAA-based daily averages through Sept. 17 show Michigan up 45 cents on the week, to $4.75. Indiana, the cheapest state, still rose 36 cents. Ohio and Wisconsin each rose 33 cents. Illinois rose 29 cents.

Those are larger seven-day moves than California’s 19-cent rise or Nevada’s 18 cents, even though the West starts from a much higher base. One-day AAA readings between Wednesday and Thursday added another jolt: Iowa up 25 cents, Wisconsin up 23, Michigan up 22.

THE WEEK’S SHARPEST STATE JUMPS

• Michigan: Up 45 cents on the week, to $4.75, the tenth-dearest state on AAA’s list.
• Indiana: Up 36 cents on the week and still the cheapest state, at $3.92.
• Ohio and Wisconsin: Each up 33 cents, a Midwest pair moving together.
• Illinois: Up 29 cents, to $4.78, which put it inside the national top ten.

A cheap-state driver can still have a brutal week if the local average leaps 30 or 40 cents before payday. That is the political risk in Ohio, Michigan, and Wisconsin, where the absolute price is not California’s and the weekly shock is larger.

Crude Settled Near $102 With Hormuz Disrupted

AAA tied the latest pump rise to crude near $100 and to swings around the Strait of Hormuz oil transit chokepoint. The United States and Israel launched strikes on Iran on Feb. 28. More than six months later, tanker traffic through that strait is still the hinge in the oil market.

Natasha Kaneva, a commodities strategist at JP Morgan, told clients the desk no longer had a baseline view of the conflict. “We simply don’t know how to model the endgame,” she wrote. Doug Johnson, a spokesman for AAA’s Mountain West group, put the same oil math in plainer words: crude remains high, averaging $100 a barrel, amid continued volatility in the strait.

FROM THE FIRST STRIKES TO THE DIESEL RECORD

1. February 28, 2026: U.S. and Israeli strikes on Iran begin, and fuel costs start their long climb from late-winter levels.
2. May 21, 2026: AAA’s national regular average hits this year’s high of $4.56, then eases through parts of summer.
3. September 14, 2026: EIA’s weekly diesel survey prints $6.285, with California at $8.039.
4. September 16, 2026: President Donald Trump, speaking in Gastonia, North Carolina, calls higher fuel costs an inexpensive price to pay.
5. September 17, 2026: AAA regular averages $4.44 and diesel sets a record at $6.40.

Gasoline had already been back above $4 for long stretches since spring. Treating Sept. 17 as a one-week scare misses that plateau. The new information is diesel’s record, stacked on crude that is still holding a triple-digit handle, with no clean model for how the strait reopens.

Brown’s Tracker Puts Extra Fuel Costs Near $107 Billion

Brown University’s Climate Solutions Lab runs an Iran War Energy Cost Tracker that compares actual AAA pump prices with a no-war baseline, then applies federal consumption data. The lab’s latest widely cited reading puts extra gasoline and diesel spending near $107 billion since Feb. 28, including about $59 billion on gasoline and about $48 billion on diesel. That estimate also folds in fuel-market damage tied to the Russia-Ukraine war.

Researchers have described the extra burden as more than $500 million a day and more than $750 per household, a household figure taken before the latest diesel surge. Jeff Colgan, the political scientist who directs the lab, has called it money coming directly out of consumers’ pockets. He has also noted a cost the model does not fully count: people who stop driving trips they would have taken at last year’s prices.

The $107 billion is not what Americans spent on fuel in total. It is the slice the lab attributes to the war-period gap versus its baseline. Commerce Department spending on fuel was already in the hundreds of billions last year. The tracker is a running tab for the premium, and the premium is still growing while crude holds near $100.

Trump Tells Gastonia the Pump Price Is Inexpensive

At a Sept. 16 rally in Gastonia for Republican Senate nominee Michael Whatley, Trump answered the fuel complaint head-on. He did not deny the gallon costs more. He asked the room to treat it as the cost of the war.

It’s a very inexpensive price to pay for what we’ve done. Remember that. It’s a little more. Frankly, even if it was a lot more. But that’s going to come tumbling down.

Donald Trump, President, Gastonia, N.C., rally, Sept. 16, 2026

He added that prices would fall “like rocket ships in reverse.” In earlier remarks this month he has said oil would drop after the November midterms, and that gasoline could eventually fall below $2. AAA’s own note is less dramatic. It said pump prices are back to spring levels and are moving toward the May 21 high of $4.56, not toward $2.

The political clock is the part he cannot talk past. Regular gasoline is $1.24 above last year and still 12 cents shy of this year’s peak. Diesel is already in the record book at $6.40. Brown’s extra-cost tally is in the $107 billion range and rising. Kaneva’s desk still has no endgame to model. The map of state gasoline prices will keep making the nightly graphic. The freight gallon is the one already rewriting the receipt.