A disagreement over trucks has become one of the clearest symbols of how close Canada and the United States came to a trade agreement — and how quickly the negotiations unravelled. U.S. Trade Representative Jamieson Greer says Canadian officials were aware that tariff relief being discussed for automobiles would not extend to medium- and heavy-duty trucks. Ottawa disputes that account, arguing that the exclusion emerged as the proposed deal was being finalized and would have put major Canadian plants at a lasting disadvantage.
The distinction may sound technical, but billions of dollars in investment and thousands of manufacturing jobs sit behind it. With trade channels now effectively frozen, the argument over which vehicles qualified for relief is becoming part of a much larger battle over the future of North American manufacturing.
Greer Says the Truck Exclusion Was Understood
Greer has pushed back directly against the Canadian government’s account of the final days of negotiations. In an August 26 interview with CBC News, the U.S. trade representative said Washington had been clear about what it could offer on automotive tariffs. The proposed arrangement would have lowered the tariff burden on cars and light trucks, while medium- and heavy-duty trucks would remain subject to a separate U.S. trade measure. Greer portrayed the broader package as exceptionally favourable to Canada and argued that Canadian negotiators sought additional changes after an initial understanding had been reached.
Ottawa describes those final days differently. Prime Minister Mark Carney has said the United States introduced terms late in the process that changed the economics of the proposed agreement, including the treatment of heavier Canadian-built vehicles. Canadian officials believed a reduced automotive tariff would apply more broadly, while the final U.S. position maintained a higher rate for medium- and heavy-duty products. That disagreement is important because it remains a dispute over what negotiators understood, not simply over a publicly documented tariff schedule. Each government is effectively accusing the other of changing the deal at the finish line.
Heavy Trucks Really Do Sit Under a Separate U.S. Tariff Regime
There is a legal reason Washington treats heavier trucks differently. President Donald Trump’s March 2025 Section 232 action imposed a 25% tariff on imported passenger vehicles and light trucks, with special provisions allowing qualifying Canadian and Mexican vehicles to pay the tariff only on their non-U.S. content. Later that year, the White House issued a separate Section 232 proclamation covering medium- and heavy-duty vehicles, their parts and buses. Most covered trucks were also assigned a 25% additional duty when the measure took effect in November 2025.
That separation gives substance to Greer’s argument that medium- and heavy-duty vehicles were a distinct negotiating category. It does not, however, prove what was promised during confidential talks. Canada has long viewed broad access to the American vehicle market as central to the North American manufacturing model. The 2018 Canada-U.S. Section 232 side agreement specifically provided protections for Canadian passenger vehicles, light trucks and automotive parts. The newer heavy-truck regime created an additional layer that negotiators now have to untangle, turning what once looked like a sector-wide discussion into a debate over individual vehicle classifications.
Oakville and Oshawa Put Real Factories Behind the Dispute
For Ontario, the argument is far more concrete than tariff terminology. Ford is preparing its Oakville Assembly Complex to build F-Series Super Duty trucks, part of a roughly US$3-billion expansion announced in 2024. About US$2.3 billion was earmarked for Oakville assembly and stamping operations, with Ford planning capacity of up to 100,000 Super Duty trucks annually. The company said the program would initially secure roughly 1,800 jobs at Oakville and generate additional engine work in Windsor. Production preparations have continued into 2026, making future access to the U.S. market increasingly important to the investment case.
General Motors has an equally visible stake in Oshawa. The plant builds both light-duty and heavy-duty Chevrolet Silverado pickups and passed 500,000 trucks produced since its 2021 reopening earlier this year. GM has also committed hundreds of millions of dollars to prepare Oshawa for its next generation of full-size gasoline-powered pickups. Carney specifically pointed to Ford’s heavier Super Duty products and GM’s truck production when explaining why Ottawa considered the proposed U.S. exclusions economically unacceptable.
Autos Were Already the Hardest Part of the Negotiations
Automotive tariffs were causing problems before the final truck dispute erupted. Reporting during the negotiations indicated that Canada was pressing for a lower tariff rate or a broader exemption based on the large amount of U.S.-made content already incorporated into Canadian vehicles. Washington had been unwilling to go as low as Canada wanted. The compromise under discussion was a rate around 15% for certain Canadian vehicles, compared with the existing 25% Section 232 tariff structure, but that relief did not ultimately cover the heavier vehicle category at the centre of the dispute.
That difference matters because Canada is extraordinarily dependent on the American vehicle market. The federal government estimates that more than 90% of Canadian-made vehicles are exported to the United States. Statistics Canada has also calculated that U.S. demand accounted for 76.4% of output and payroll jobs in Canada’s automobile and light-duty vehicle manufacturing industry in 2024, supporting roughly 27,000 jobs in that segment. When a tariff rate changes by ten percentage points, the consequences can therefore reach beyond customs bills into production schedules, sourcing decisions and future factory investment.
The Supply Chain Makes a Clean Canada-U.S. Split Difficult
North America’s auto industry was designed around integration rather than national self-sufficiency. Under CUSMA’s automotive rules, qualifying vehicles generally need 75% regional value content, alongside requirements for core components, North American steel and aluminum, and labour value. Engines, transmissions, electronics and other components can move through a network of plants before a finished vehicle reaches a dealership. Canada’s own description of the continental supply chain notes that a vehicle can cross borders several times during production.
The scale makes disruption costly. Canadian motor-vehicle manufacturers exported about C$45.2 billion in products to the United States in 2025, far more than to any other individual market. Statistics Canada has simultaneously documented weakening employment in parts manufacturing as tariff uncertainty has weighed on the sector. This is why a truck built in Ontario cannot easily be treated as economically separate from American manufacturing. Ford’s Super Duty program, for example, draws on engines, transmissions, axles and components produced across plants in both countries. Tariffs aimed at Canadian assembly can therefore change demand for American-made inputs as well.
The Truck Fight Has Spilled Into a Much Larger Trade War
The failure to reach an agreement has already moved beyond automobiles. The United States imposed 50% tariffs on C$27.6 billion worth of targeted Canadian goods effective August 22. Ottawa responded by announcing matching countermeasures covering C$27.6 billion of U.S. imports, with Canadian rates of 15%, 25% and 50% scheduled to begin September 8. The affected categories include steel, dairy, appliances, agricultural equipment, pulp and paper, electronics and other products. Existing Canadian counter-tariffs on U.S. autos and certain strategic sectors remain separate from the new package.
Ottawa has also announced C$7.5 billion in new and enhanced assistance for workers and businesses affected by the dispute, on top of earlier support programs. Washington, meanwhile, has escalated its automotive threat. Trump has said Canadian cars, trucks and automotive parts could face tariffs of 50% beginning January 1, 2027 if the confrontation continues. A disagreement that initially centred on whether heavy trucks received a 15% or 25% treatment could therefore evolve into a much larger barrier affecting virtually the entire Canadian vehicle industry.
Closed Channels Make the Next Step Harder to Predict
Perhaps the most consequential part of Greer’s recent comments was not his interpretation of the truck negotiations but his description of the relationship afterward. He said he and Canada-U.S. Trade Minister Dominic LeBlanc did not currently have open negotiating channels. Canadian officials have similarly indicated that Ottawa is not prepared to return simply to restore dialogue without a meaningful shift in Washington’s approach. There have been limited signs of clarification on individual disputes, including questions surrounding French-language measures, but no broad restart has been announced.
CUSMA itself remains in force and is scheduled to continue until 2036 unless its review and extension mechanisms ultimately change that path. That provides a legal framework beneath the political fight, but it does not erase the new tariffs layered on top of continental trade. If negotiations resume, the treatment of Canadian trucks will probably have to be written with far greater precision than before. For Oakville, Oshawa and the supplier communities surrounding them, the difference between a car, a light truck and a heavy truck has suddenly become an economic dividing line.
