US diesel hits record $5.90 a gallon as US-Iran fighting and refinery strikes tighten supply
Diesel hit a record $5.90 a gallon this week, according to AAA. That price feeds straight into costs for anyone who hauls freight or prices fuel at a c-store. Gasoline topped $4 nationally over the Labor Day weekend, a record for the holiday. Both moves trace back to the same place: a shooting war involving US forces in the Gulf, and a separate campaign of strikes on Russian refineries that has pulled diesel out of the global pool.
The diesel record
$5.90 is the pump average AAA published this week, with $5.89 showing up in some feeds a day earlier. The driver is distillate supply, not demand. Refiners worldwide are running to make diesel, and it still is not enough to keep the retail number down.
A record wholesale diesel print squeezes the jobber's margin unless you are passing it through fast, and your haulers eat the same cost on every load. Freight surcharges follow diesel with a lag, so the squeeze lands on the operator first.
Crude and the Gulf
WTI was trading around $92.14 and Brent around $96.89 early this week after another weekend of escalation. US Central Command said it struck three Iranian oil tankers, the M/T Downy and M/T Star among them, in response to the IRGC targeting two US warships with ballistic missiles. Iran vowed revenge.
Goldman Sachs put a number on the tail risk. Daan Struyven, co-head of global commodities research, told Bloomberg TV that oil could reach as much as $120 a barrel if attacks on shipping in the region broaden. His words were that the risk of disruptions "broadening and intensifying is an important one." That is a scenario, not a call, and the roughly $23 gap between today's Brent and that figure is the war premium the market has not yet priced.
Watch the Strait of Hormuz. QatarEnergy looks to be preparing to restart LNG loadings, with six empty carriers tracked heading toward the Gulf and one already across the strait, per Kpler data cited by Bloomberg. If Qatari gas is moving through Hormuz again, the market is betting the chokepoint stays open. Crude could ease if it does.
The Russian refinery link
Energy Secretary Chris Wright tied the record US diesel price directly to Ukrainian strikes on Russian refineries. Zelensky confirmed hits on Russian oil-processing plants in Ryazan and Perm, another in Tatarstan, plus an asset in the Black Sea. Russia is a large exporter of diesel and refined products, and taking processing capacity offline pulls barrels out of the seaborne market that Europe and Asia would otherwise buy. That backs up into US export demand and lifts the whole distillate curve.
For a US operator, the competition is no longer a refinery outage in Louisiana. It is the whole Atlantic basin buying the same diesel. When Russian supply drops, buyers everywhere reach for US Gulf Coast barrels, and the export pull tightens what is left at home.
Bunker fuel squeezed
Refiners chasing diesel margins are making less bunker fuel. Fuel oil for marine bunkers is getting squeezed, with Energy Aspects putting the shortfall at 218,000 barrels a day this quarter, per Reuters. That would be the first quarterly bunker shortage since 2025, when the gap was only about 6,000 barrels a day. Asia takes the worst of it.
To a US operator this confirms the barrel is going to diesel first and everything else second. As long as diesel cracks stay this wide, refiners will keep making the high-value cut and let heavier products go short.
OPEC's October plan
OPEC+ revealed its October output plan this week, per Rigzone. The group's decisions on returning barrels are the main lever that could soften crude from here if there are no new attacks in the Gulf. New supply is returning from members that had held output back, and more of it would push against the war premium. Prices look set to soften if OPEC keeps adding barrels and Hormuz stays open, and to stay bid if either changes.
Gas at $4
Retail gasoline crossed $4 nationally as US-Iran tensions escalated, and Labor Day pump prices set holiday records in Chicago and across several markets. Drivers are stretching mileage to cope. Boaters got safety warnings tied to high fuel costs over the weekend.
Higher pump prices are showing up as a live cost-of-living issue in at least one toss-up congressional district. That is worth tracking, because political pressure on fuel prices tends to produce policy noise like release talk and tax-holiday proposals.
Corn, crush, and a Texas gas plant
Domestic biofuel demand held firm. The USDA reported 222 million bushels of soybeans crushed in July, 4 million above June and 17 million above a year ago, on strong margins and solid product uptake. Ethanol output stayed high, keeping corn demand elevated. Anyone blending or moving renewable diesel and ethanol feedstock can read the crush strength as a sign the domestic pull for soy oil is real and steady.
South Korea agreed to invest $22.3 billion in a 6.3 GW gas-fired plant in Texas to power AI data centers, its first project under a trade deal with the Trump administration and part of a $350 billion pledge. That is a long-dated demand story for US natural gas, not a this-week price move, but it points to where domestic gas offtake is heading as data-center load builds.
What to watch
Hormuz first. If Qatari LNG resumes moving through the strait and no tanker gets hit, the war premium in crude could bleed off and diesel with it. If the US-Iran exchange widens to shipping, Goldman's $120 scenario stops being hypothetical.
Watch whether Ukraine keeps hitting Russian refineries and how fast that capacity comes back, because that is the direct lever on the diesel record. Watch OPEC+'s October barrels actually showing up versus being promised. And watch the bunker shortage: if it forces shippers to bid up middle distillates as a substitute, that adds another claim on the same diesel you are trying to buy.