US Diesel Sets an All-Time Record at $5.98 as Pump Prices Defy the Autumn Lull
AAA's national diesel average hit a record on 10 September and petrol jumped 13 cents in a week, reversing the usual post-summer slide as distillate stocks run low.
The average price of diesel in the United States reached $5.977 a gallon on Thursday 10 September, according to the motoring organisation AAA, the highest national average it has ever recorded. Regular petrol climbed to $4.277, up about 13 cents in a single week.
The record comes less than a week after diesel pushed to its highest level since 2022. It also runs against the calendar. Pump prices normally drift lower after the summer driving season ends, but this year they have climbed back to levels last seen in early June.
Context: a fuel market squeezed from both ends
The immediate trigger is crude. Brent returned to the $100-a-barrel range this week for the first time since July as risks to shipping around the Strait of Hormuz intensified, and retail prices follow crude with only a short lag.
Diesel's climb has outpaced petrol's because the squeeze is also happening at the refinery gate. Distillates, the family of fuels that includes diesel, heating oil and jet fuel, are in short supply worldwide. The US Energy Information Administration expects American distillate inventories to fall below 100 million barrels this month and to remain under their five-year average for much of 2027. Refining margins on petrol are elevated too: since May, the spread between crude and wholesale gasoline has averaged roughly $1 a gallon more than in 2025, the EIA says, reflecting tight global gasoline supply.
The year-on-year comparison shows the scale of the shift. A year ago AAA's diesel average stood at $3.706, so today's price is about 61% higher. Regular petrol is up around 34% from $3.194.
Why it matters
Diesel is the fuel of the physical economy. It powers long-haul lorries, freight trains, tractors, construction machinery and many backup generators, so a sustained rise works its way into the cost of almost everything that has to be moved, built or harvested. The timing is awkward for farmers heading into harvest, and for households in the north-east that heat their homes with oil drawn from the same pool of distillate stocks.
Petrol is the price most voters see. With the midterm elections less than two months away, a 13-cent weekly jump on the forecourt sign is the kind of change that campaigns notice quickly.
- Diesel: $5.977 a gallon on 10 September, AAA's highest ever, against $5.783 a week earlier and $5.300 a month earlier.
- Regular: $4.277, against $4.144 a week ago and $4.009 a month ago. The all-time record of $5.017 dates from June 2022.
- Higher grades: mid-grade averaged $4.778 and premium $5.165.
- Electric charging: the average public charging rate was unchanged at 42 cents per kilowatt-hour.
- Inventories: the EIA sees US distillate stocks dropping below 100 million barrels in September.
Outlook
The EIA's latest outlook, completed on 3 September before this week's jump in crude, projects retail diesel averaging about $5.55 in the final quarter of 2026 before easing to an average of $4.40 across 2027 as supply recovers. Thursday's price is already well above that fourth-quarter path.
Whether it stays there depends on two things that are hard to forecast: how quickly export flows from the Gulf return to normal, and whether refiners can rebuild distillate stocks before winter heating demand arrives. Until at least one of those improves, relief at the pump is likely to be slow in coming, and diesel users in particular should expect elevated costs well into the autumn.
Image: The Bushranger via Wikimedia Commons, CC BY-SA 4.0