U.S. diesel averaged $6.382 a gallon on Sept. 28, up $2.628 from a year earlier, according to the Energy Information Administration. That is a 70% jump in 12 months. Regular gasoline stood at $4.465, up $1.347 or about 43%, and AAA said Thursday’s national average of $4.41 followed the most expensive September on record. The cost of diesel has begun to drive policy. Gov. Greg Abbott declared a statewide disaster over diesel on Sept. 28, and other states have moved on fuel tax relief.
Diesel price numbers from the EIA
The EIA’s weekly survey showed diesel down 14.7 cents from the prior week and gasoline down 1.3 cents. The West Coast was the most expensive region for gasoline at $5.724 a gallon. The Gulf Coast was cheapest at $3.924. California led all states at $6.189. Gasoline retail prices break down this way, per the EIA: crude oil makes up 52%, refining 22%, distribution and marketing 15% and taxes 12%. Crude is the largest share, which is why the move in oil matters most.
The EIA’s September outlook, released Sept. 9, said Brent crude would average around $90 a barrel in the second half of 2026. The agency said global oil inventories have fallen by an estimated 400 million barrels this year and that constraints on exporting oil from the Middle East would persist through the end of the year. The outlook also said tightness in the global distillate market has raised U.S. prices and encouraged exporters to ship more.
Record September at the pump
AAA reported that September’s average for regular gasoline was $4.33, 50 cents above the previous September record set in 2023. The national average fell to $4.4137 on Oct. 1 from $4.4825 a week earlier. Crude had slipped back to the $90 range, and gasoline demand fell from 8.84 million to 8.68 million barrels a day.
“Drivers are finally seeing some welcome relief,” said Jana Tidwell, a spokesperson for AAA Club Alliance, according to a regional AAA release. Prices are still the highest ever recorded for this time of year. California was at $6.40 on Oct. 1, Hawaii at $5.62 and Washington at $5.49. Indiana was lowest at $3.81. In Texas, Fox 4 reported that the September average of $3.94 topped the old September record of $3.63 from 2012. The all-time state record of $4.69 dates to June 2022. Texas diesel disaster declaration and its limits
Abbott’s proclamation covers all 254 Texas counties. According to Fox 7 Austin, it lifts limits on using untaxed dyed diesel on public roads, allows gross weights up to 95,000 pounds for vehicles hauling fuel, farm or timber products, and suspends Texas Low Emission Diesel rules to the extent federal law allows. Abbott also asked the Environmental Protection Agency for a waiver on ultra-low-sulfur diesel in 110 counties.
“Texas agriculture and freight run on diesel,” Abbott said, according to Fox 7. Fox 7 reported Texas diesel set a record of $5.97 a gallon in September. Newsweek listed Texas as the cheapest state for diesel on Sept. 30 at $5.86, against $8.39 in California and a $6.45 national average. Patrick De Haan, a petroleum analyst at GasBuddy, said the dyed-diesel waiver will do little. “Taxes aren’t the problem, supply is,” he told Newsweek. He estimated that dyed diesel saves truckers about 44 cents a gallon in taxes and said farmers already use it and still pay record prices.
Why diesel costs more than gasoline
The gap between the two fuels is the part of the data that gets less attention. On Sept. 28 diesel sold for $1.917 a gallon more than gasoline. A year earlier the gap was about 63 cents. Diesel rose 70% against gasoline’s 43%. The 44 cents De Haan cited equals about 7% of the $6.38 national price. It would cover roughly a quarter of the current gap with gasoline.
The EIA’s September outlook projected a 2026 average of $5.07 for retail diesel. The weekly figure is $1.31 above that, a sign the agency’s forecast for the year depends on a decline in the fall. Newsweek attributed the surge to disruption of oil shipping through the Strait of Hormuz. Fox 7 reported that Russia’s July diesel export ban and U.S. distillate stocks at their lowest seasonal level since 1982 added to the squeeze. Georgia and California have also enacted fuel tax relief ahead of the November midterms, according to Newsweek.
Inflation data show where the cost lands. The Bureau of Labor Statistics said in its August consumer price report that gasoline rose 3.9% in the month and accounted for over one-third of the 0.4% overall increase. Energy was up 16.3% from a year earlier, and consumer prices rose 3.4% over 12 months. The September report is due Oct. 14.
