Updated October 8, 2026, 7:29 a.m. ET
When you fill up the tank and your eyes turn to the diesel pump, you might shake your head and thank your lucky stars that your car doesn’t run on diesel.
But much of the U.S. economy runs on diesel, from tractor-trailers to delivery trucks to agricultural combines. And sky-high diesel prices eventually trickle down to the country’s supermarkets and warehouse stores, driving up prices for a wide range of goods and services.
Here is the impact of the high price of diesel on the American consumer
Who uses diesel?
Only about 3% of passenger vehicles use diesel (mainly used imported pickup trucks, SUVs and sedans), but 76% of commercial vehicles use diesel.
“Diesel is the most efficient fuel in the economy,” said David Ortega, a food economist at Michigan State University. “Semi-trailers, freight trains, barges and farm machinery travel there. Most consumers never buy a gallon of diesel, but almost everything they buy has been transported on diesel at some point, often multiple times, between production and the store shelf.”
How much does diesel cost?
A gallon of diesel cost an average of $6.30 on Oct. 7, compared with $5.90 a month earlier and $3.68 a year ago, according to AAA. The current price is just below the all-time high of $6.53, set on September 22.
Diesel prices are even higher in California, a leading producer of dairy, nuts, grapes, lettuce, strawberries and other crops. A gallon of diesel in California cost $8.35 on October 7.
If diesel prices continue to rise, “some pumps aren’t even built to show what might happen next,” oil analyst Patrick De Haan tweeted in early September.
Why is diesel so expensive?
Fuel prices are rising everywhere because of the war in Iran. The conflict has restricted oil tanker traffic through the Strait of Hormuz and triggered attacks on refineries and infrastructure in the Persian Gulf. Another factor is attacks on Russian refineries during the war in Ukraine.
Diesel costs are even higher due to strong global demand, high excise taxes and other factors.
How do high diesel prices affect farmers?
For farmers, the timing of the diesel price surge “could hardly be worse,” Ortega said. “We are in the heart of the fall harvest, when combines, tractors, grain carts and trucks spend long hours moving crops from fields to warehouses and elevators. »
A combine operation uses approximately 300 gallons of diesel per day. In California, that’s about $2,500 worth of fuel.
Wayne Gularte, who farms 600 acres near Gonzales, Calif., told Reuters his fuel costs had increased 40 percent this year, from about $5 a gallon to $7. To cut costs, he brought a 1950s gasoline tractor back into service.
Nationally, farm fuel costs are up $18 an acre, or 82 percent, from last year for corn, and $11 an acre, or 79 percent, for soybeans, two of America’s top crops, said Michael Langemeier, an economist at Purdue University.
How do high diesel prices affect consumers?
Diesel prices have increased by around 75% compared to last year. Fortunately for consumers, only a fraction of this increase will reach warehouses and stores.
The fuel used to transport and store food, for example, accounts for 4 to 7 percent of its total cost, said Bernhard Dalheimer, an agricultural economist at Purdue.
“Now it’s just an average,” he said. Fuel can represent a much higher portion of the total cost of some items.
Here are some examples.
Food transported long distances
If you dine at Five Guys, you may notice that the potatoes often come from Idaho. Idaho is far from most of the continental United States, and trucks must transport potatoes several miles to reach your local hamburger restaurant.
“A truckload of potatoes from Idaho to Chicago costs 40 percent more than it did a year ago, and half of that is diesel,” said Jason Miller, a professor of supply chain management at Michigan State University.
The same economic principles apply to apples and pears grown in Washington’s Yakima Valley as well as lettuce and strawberries from California, said Dean Croke, senior analyst at DAT Freight & Analytics.
Perishable foods requiring refrigeration
Almost everything that is refrigerated at the supermarket is also refrigerated on its way to its destination. Transporting these goods requires refrigerated trucks, which consume a lot of diesel.
“Fresh produce, dairy and meat often travel long distances in refrigerated trucks that burn energy both moving and keeping the products cold,” Ortega said.
Factoring in refrigeration and distance, shipping a truckload of lettuce from Salinas, Calif., to New York “will cost about $10,000,” Croke said, and $4,200 of the total is for diesel alone. A year ago, Croke said, the same fuel would have cost about $2,700.
Heavy and low value products
Let’s take a case of soda. It’s mostly water. Water is heavy: about eight pounds per gallon. The soda is relatively inexpensive to bottle, but expensive to ship. This is why soda manufacturing companies have factories near large population centers.
Heavy, cheap products are particularly vulnerable to diesel prices because “transportation is a significant part of what you pay for them,” Ortega said.
The list includes bottled drinks, canned goods and a range of non-food products including household appliances.
If you buy mulch for a dump truck, “that nursery is probably going to charge you extra for fuel,” Miller said.
What other products and services are impacted by high diesel costs?
Here are some examples.
Fuel oil
Diesel fuel and heating oil are essentially “the exact same product,” said Alex Jacquez, senior vice president of policy, advocacy and research at Groundwork Collaborative. And nearly 5 million homes, mainly in the North-East, still use fuel oil.
Fuel oil prices have risen sharply this year.
Shipping Services
Soaring diesel prices have prompted shipping services to increase fuel surcharges, which rise and fall based on diesel prices per gallon.
At UPS, the domestic ground surcharge increased from 25% on July 6 to 29.5% on September 21. The rate rose to 30.25% on September 28.
At FedEx, the surcharge for ground service is 29.25%.
Diesel costs will drive up the prices of gifts we ship for the holidays, Miller said. Retailers will find ways to integrate the surcharge into the tab.
“You might see higher minimum order quantities for free shipping and things like that,” he said.
What is the end result?
Unless you buy heating oil or drive a vintage BMW, you’re not likely to experience the full brunt of diesel at $6.50 a gallon.
The impact of high diesel prices on a package of lettuce or a bag of potatoes will be measured in cents on the dollar, Miller said.
For what? Because fuel costs are only about 5% of the average sticker price you pay at the supermarket. If shipping costs double, a $1 potato could become a $1.05 potato.
And it takes months for price shocks to ripple through the supply chain.
Contract prices between manufacturers and retailers are often set annually, Miller said. So the full effects of rising diesel prices may not be felt “for at least six to nine months, at a minimum,” he said.
“Initially, a lot of the increased costs are absorbed throughout the supply chain,” Ortega said. “But as contracts are revised and fuel surcharges kick in, more of those costs end up in grocery stores.”
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