The national average price for on-highway diesel jumped another 32 cents this week to $6.285 per gallon, according to data released Sept. 15 by the U.S. Energy Information Administration (EIA). That a 5.3% increase week over week and whopping 68% over diesel price from the same week last year.

The national average price for regular gasoline also rose 16 cents this week to $4.319, according to the EIA.

For trucking fleets, the increase adds another layer of operating cost pressure. The latest study by American Trucking Research Institute (ATRI), called “Analysis of the Operational Costs of Trucking: 2026 Update,” found that carriers’ total average marginal cost per mile reached $2.33 in 2025, a 3.4% increase year over year. Maintenance rose 8.6% from 2024 to 2025. The new fuel increases will not be absorbed completely by carriers due to fuel surcharge mechanisms, but fleets are feeling a sting.

Jamie Hagen, president of Hellbent Xpress, told News Nation this week that his fleet is "paying double from what we usually pay" and "it's hurting, it's hurting bad...right when things were supposed to be coming back and moving good."

Hagen has always been focused on mpg, purchasing several new Mack Pioneers in the last year for their fuel efficiency gains. Spec'ing trucks with integrated powertrains and lowering rear-axle ratios, but managing driver behavior is the most direct and immediate method, though. 

"We're attempting to slow down; that is the cheapest way to get fuel economy," he told News Nation.

Now if only the fuel hikes would ease up.

Why is this happening?

The increase comes as disruptions to oil and shipping traffic around the Strait of Hormuz continue to put pressure on global markets. Crude oil prices have moved above $100 per barrel as the conflict involving the U.S. and Iran continues, while disruptions affecting regional energy infrastructure have added to concerns about global oil supplies.

President Trump said September 14 that the U.S. is open to negotiating a deal with Iran, a shift from earlier comments questioning whether an agreement with the country would hold.

"The failing Nation of Iran wants to make a deal, quickly and badly. I will determine whether or not the U.S.A. will choose to engage—the concept of which we are open to,” he wrote on Truth Social. 

Trump also blamed Ukraine for attacks on Russian refineries as a reason for the surging prices.

What are current diesel prices across the U.S.?

Every EIA region saw diesel prices increase this week.

• East Coast: Diesel increased 41 cents to $6.158 per gallon.
• Midwest: Diesel increased 30 cents to $6.250.
• Gulf Coast: Diesel increased 27 cents to $6.027.
• West Coast: Diesel increased 26 cents to $7.250. Excluding California, the average increased 25 cents to $6.566.
• Rocky Mountain: Diesel increased 26 cents to $6.066.

The West Coast remains the only region with an average above $7 per gallon, while the Gulf Coast has the lowest regional average at $6.027.

What are current gasoline prices across the U.S.?

The EIA reported a national average gasoline price of $4.319 per gallon, up 16 cents from the previous week and $1.151 higher than a year ago.

Regional averages were:

• Midwest: $4.091, up 20 cents.
• Gulf Coast: $3.852, up 17 cents.
• East Coast: $4.191, up 16 cents.
• Rocky Mountain: $4.438, up 12 cents.
• West Coast: $5.467, up 11 cents. Excluding California, the average increased 5 cents to $5.026.

AAA also has attributed the recent increase in pump prices to volatility around the Strait of Hormuz, noting that crude oil had returned to the $100-per-barrel range earlier this month.

For fleets, the immediate takeaway is unfortunately straightforward: fuel remains a significant and rising operating expense, with diesel prices now more than $2.50 per gallon above where they were a year ago.