Diesel has become the latest pressure point in a North American freight system already absorbing higher trade, labour and financing costs. The U.S. national average reached a record $5.9015 a gallon on September 7, according to AAA, roughly $2.19 above the same day a year earlier. For carriers that cross the Canada-U.S. border, the jump lands directly on the cost of moving food, auto parts, machinery and consumer goods.
The shock matters because trucks remain the dominant mode for Canada-U.S. merchandise freight. Even when fuel surcharges recover part of the increase, the timing can squeeze cash flow and leave smaller fleets exposed. The result is a cost spike that can travel from the truck stop to shipping invoices, warehouse budgets and, eventually, store shelves.
Diesel Has Moved Into Record Territory
AAA’s September 7 reading of $5.9015 a gallon put U.S. diesel at the highest national average in its records. One week earlier, the same benchmark was $5.6002, and a year earlier it was $3.7088. That means the latest increase is not simply a slow inflationary drift. It is a sharp move in a fuel that sits at the centre of long-haul trucking, construction and agriculture.
Different price trackers publish at different speeds, so the numbers do not always match on the same day. GasBuddy reported a record $5.820 on September 3, just above its previous June 2022 peak of $5.819. The U.S. Energy Information Administration, whose weekly series lags the daily trackers, listed $5.599 for August 31 and is scheduled to publish its next weekly update on September 9. The direction across all three measures is nevertheless unmistakable: diesel has moved into record territory for North American freight operators.
Diesel Is Outrunning the Crude-Oil Market
Diesel is rising faster than crude alone would suggest. Around Labor Day, West Texas Intermediate was trading near $92 a barrel and Brent near $97. Refined diesel has been rising faster because the market is short not only of crude, but also of the refinery capacity and product flows needed to turn crude into usable fuel.
Reuters reported that the U.S. diesel crack spread, a common measure of refinery profit on converting crude into diesel, reached a record $108.02 a barrel as the supply squeeze intensified. Ukrainian attacks on Russian refineries have reduced exports from a major diesel supplier, while war-related disruptions in the Persian Gulf have restricted another important source. In practical terms, a barrel of crude can be available while the diesel made from it remains scarce. That disconnect is why pump prices can keep climbing even when crude stays below peaks across today’s strained global market.
The Strait of Hormuz Shock Is Still Working Through Supply
The Strait of Hormuz remains central to the shortage. EIA estimated that crude oil and petroleum liquids moving through the strait averaged just 4.9 million barrels a day in the second quarter of 2026, down from 21.6 million in the fourth quarter of 2025. Petroleum-product flows through the route fell to about 1.1 million barrels a day from 5.7 million over the same comparison.
The wider refined-fuel market is also stretched. The International Energy Agency said diesel exports from Russia, the Middle East and Asia were 1.3 million barrels a day lower year over year in July, equal to roughly 20% of global seaborne diesel trade. U.S. refiners have responded by exporting more product, with EIA reporting distillate exports of 1.6 million barrels a day in April, the highest since 2017. That helps overseas buyers, but it also means U.S. truckers are competing in a market shaped by global scarcity.
Cross-Border Trucking Has Too Much Exposure to Ignore
Cross-border trucking is too large for a fuel shock of this size to stay local. U.S. Bureau of Transportation Statistics data show Canada-U.S. freight totaled $67.9 billion in June 2026, with trucks carrying $35.9 billion of that amount. For all of 2025, trucks moved about $396.8 billion in freight between the two countries, representing 55.7% of the total value.
That scale is visible on the ground at places such as Detroit, Port Huron and Buffalo, which BTS identifies as the leading U.S. truck gateways for trade with Canada. A tractor leaving Windsor with auto components may cross into Michigan, deliver to a plant and then pick up another load before returning north. Higher U.S. diesel affects each leg differently depending on where the truck fuels and how the contract handles surcharges. Multiplied across thousands of shipments, a few extra dollars at every fill-up quickly becomes a material logistics expense nationwide.
Fuel Surcharges Move Fast, but Not Always Instantly
Fuel surcharges are designed to keep a sudden pump-price move from crushing carriers, but they do not make the shock disappear. They typically use a published fuel benchmark and adjust freight bills according to a formula. Because those formulas are often weekly or monthly, there can be a lag between the price a carrier pays today and the surcharge it can recover from a customer.
Canadian carrier schedules show how large those adjustments have become. CDI lists a cross-border truckload fuel surcharge of 86.4% and a cross-border less-than-truckload surcharge of 50.5% for the week beginning September 7. Canadian Alliance Terminals lists a 90.7% truckload fuel index for that period. These are company-specific schedules, not universal industry rates, but they illustrate the pressure moving through freight invoices. For shippers, the surcharge appears as a transportation bill. For carriers, the risk is that reimbursement arrives after the fuel has already been bought.
Thin Trucking Margins Make the Spike More Dangerous
The latest diesel surge is landing on an industry that had little room for another cost increase. The American Transportation Research Institute found that the average cost to operate a truck reached a record $2.336 per mile in 2025, up 3.4% from the prior year. Even excluding fuel, costs climbed 4.2% to $1.854 per mile as tolls, maintenance, benefits and tires became more expensive.
Profitability was already thin. ATRI said average operating margins in truckload and refrigerated operations remained below 1% in 2025, while flatbed carriers posted an average loss of 0.5%. Fleets responded by cutting truck counts by 2.4%, leaving about 10% of trucks unseated on average and reducing non-driver staffing. That backdrop matters because a record fuel spike does not hit a healthy industry with abundant cash reserves. It hits carriers that have spent years trimming capacity and controlling expenses, making short-term cash-flow pressure important for smaller operators.
The Math on a Long-Haul Fuel Stop Has Changed
The size of the change becomes clearer with a simple fuel-ticket example. A truck that burns 150 gallons on a run would spend about $885 at a diesel price of $5.90 a gallon. At the year-ago AAA average of about $3.71, the 150 gallons would cost roughly $557. That is about $329 before considering idling, refrigerated trailer fuel or detours.
A fleet repeating that pattern across dozens of trucks can see the increase compound quickly. Fifty such fuel purchases would add more than $16,000 compared with the year-ago price level. Fuel surcharges can eventually recover some or most of that amount, depending on the contract, but the carrier still needs enough working capital to pay the card or supplier first. That is why diesel volatility can become a financing issue as much as an operating-cost issue, particularly for owner-operators and small fleets without the purchasing power of national carriers.
Canada Has a Tax Cushion, Not Immunity
Canada has added a cushion, but it cannot fully shield cross-border fleets from U.S. prices. Ottawa first suspended the federal excise tax on diesel, normally four cents per litre, from April 20 through September 7, 2026. The government then moved to extend the zero rate through January 31, 2027, with a two-cent rate planned for February and March before the full four-cent rate returns in April.
For Canadian carriers, that relief lowers the tax component of diesel purchased at home. It does not change the price paid at U.S. truck stops, nor does it erase the higher fuel surcharges charged by transportation providers. A carrier running Toronto-Chicago or Montreal-Boston may still buy fuel south of the border because of route timing, tank capacity and dispatch needs. The extension therefore softens one part of the cost structure while leaving the larger global diesel shortage intact. It is relief, but not insulation.
Food and Produce Could Feel the Pressure Quickly
Food is one area where the freight shock can become visible quickly because many products are time-sensitive and difficult to reroute. Agriculture and Agri-Food Canada reported that the United States supplied 56.6% of Canada’s field-vegetable imports by value in 2025 and 61.5% by volume. Refrigerated trucks moving produce north therefore face the same record U.S. diesel market as other cross-border carriers.
Research commissioned by the U.S. Department of Agriculture found that higher diesel prices and reduced driver availability generally raised transportation-related price spreads for apples, potatoes, tomatoes and onions, with potatoes and onions among the most sensitive. The current regional price gap adds another layer: AAA put California diesel at a record $7.8256 a gallon on September 7. Not every grocery item will rise because of fuel alone, but long-distance produce with thin margins has fewer places to absorb a large transportation increase before some of it reaches buyers.
The Biggest Question Is How Long the Shock Lasts
The outlook today depends on whether refinery and shipping constraints ease faster than seasonal diesel demand grows. EIA’s August outlook assumed Strait of Hormuz flows would remain severely constrained through August and gradually improve in September, with broader production and trade patterns taking until early 2027 to move back toward pre-conflict conditions. That is a long recovery window for a fuel market already operating with low inventories.
Prices could remain volatile even if crude stops climbing. Fall harvest activity increases diesel use, East Coast distillate stocks fell to 19.3 million barrels in late August, and OPEC+ decided on September 6 to maintain its September production requirement for October. The next official EIA weekly diesel price is due September 9, followed by the holiday-delayed petroleum status report on September 10. For cross-border trucking, the immediate question is no longer whether diesel is expensive, but how long record-level costs will persist.
