Economist Steve Hanke stated that record-high diesel prices are "crushing" American farmers and truckers during the harvest season. He argued on X that the fuel shock is a primary reason these groups are turning against President Donald Trump.

Diesel Surge Hits Farmers During Harvest

Hanke reported that farm fuel costs increased by $11 per acre for corn and $7 per acre for soybeans compared to last year. Reuters cited Purdue University economist Michael Langemeier to confirm these increases. The Energy Information Administration recorded U.S. on-highway diesel at $6.285 per gallon on September 14, a sharp rise from the previous year. Diesel crossed $6 nationally this month due to the U.S.-Iran conflict and Ukrainian attacks on Russian refineries tightening global supplies.

The timing has intensified financial pressure on agricultural operations. South Dakota farmer Drew Peterson expects to spend up to $1,500 a day fueling one combine, approximately twice last year’s cost. California vegetable grower Wayne Gularte reported a roughly 40% rise in his fuel costs.

Economists Warn Fuel Pressure Could Persist

Kansas State University economist Gregg Ibendahl warned that diesel prices could remain elevated for at least another year. He noted that farmers are price takers who must absorb higher costs without setting corn or soybean prices. American Farm Bureau economist Faith Parum stated farm diesel reached $5.45 a gallon on September 4, up from $3.02 a year earlier. University of Illinois economist Nick Paulson told Reuters that "$6-plus per gallon diesel" could create inflationary pressure on seed, fertilizer, and other inputs next year.

Truckers Struggle As Political Pressure Grows

Independent truckers face similar strain as they typically pay fuel bills upfront. DAT Freight & Analytics principal analyst Dean Croke told Reuters that further increases could trigger "diesel price-driven bankruptcies." While Hanke’s political claim suggests a broad shift, the Associated Press reported frustration among voters without establishing a widespread change in sentiment among farmers or truckers. Senator Chuck Grassley (R-Iowa) said high diesel prices are "killing farmers income" and urged an export embargo.

What the Numbers Show

The divergence between input cost inflation and revenue control is stark. While diesel prices more than doubled from $3.02 to over $6.28 per gallon, farmers remain price takers for their output commodities. This structural imbalance means the entire burden of the supply-side shock—driven by geopolitical conflicts—is absorbed directly by agricultural margins rather than being passed through to consumers.

The national average on-highway diesel price in the United States reached a record $6.285 per gallon on September 14, 2026. This figure represents an increase of nearly 69 cents in two weeks and is almost $2.55 higher than a year ago.

The Engine Technology Forum (ETF) released new analysis identifying strategies to reduce fuel consumption for industries reliant on diesel, including freight, agriculture, and construction. Allen Schaeffer, executive director of ETF, noted that diesel powers 97% of Class 8 commercial trucks and most farm and construction equipment.

Price Drivers and Impact

According to the U.S. Energy Information Administration, tight global supplies, low distillate inventories, refinery disruptions, and seasonal demand are sustaining upward pressure on prices. The current rate exceeds the previous record set in 2022.

What the Numbers Show

Operational adjustments offer significant cost mitigation potential relative to the price spike. For a truck traveling 100,000 miles annually at 6.6 mpg versus 8.0 mpg, the fuel difference is 2,650 gallons. At the current price of $6.28 per gallon, this efficiency gap translates to approximately $16,600 in additional annual expense for the less efficient vehicle. Similarly, idling for two hours daily over 250 operating days wastes roughly 400 gallons, costing about $2,512 annually.

Key Mitigation Strategies

The ETF analysis highlights several factors contributing to higher fuel costs and methods to mitigate them:

• Vehicle speed: Traveling at 70 mph uses 15% to 25% more fuel than driving at 55-65 mph.
• Engine idling: Heavy-duty engines burn 0.5 to 1 gallon per hour at idle. Construction fleets lose 30% to 40% of productive time to idling, according to Geotab.
• Maintenance: Underinflated tires reduce fuel economy by about 0.2% for every 1 psi drop in average pressure across four tires.
• Equipment age: Trucks from model year 2010 or newer use 3-5% less fuel due to selective catalytic reduction technology. Farm and construction equipment from model year 2014 or newer show similar gains.
• Alternative fuels: Biodiesel blends up to B20 and renewable diesel can help stabilize costs. A 2022 study found expanded biomass-based diesel production could lower prices by about 4%.
• Technology: AI-based routing, telematics, and precision farming tools improve productivity and reduce inputs.
• Fuel alternatives: Natural gas and propane are available for conversion, though electric options remain limited by infrastructure and upfront costs.