A car can satisfy North America’s trade rules and still arrive at the U.S. border with a tariff bill. That contradiction is becoming the central threat to Canada’s auto industry as the Trump administration pushes to rewrite CUSMA around a far more demanding idea of “American” content. Washington has reportedly proposed lifting the regional-content threshold for qualifying vehicles from 75% to 82%, while requiring 50% of a vehicle’s value to come specifically from the United States.
The proposal has not been adopted, and key calculation details remain unsettled. Yet its direction is unmistakable: Canadian assembly would no longer be treated as equal to U.S. assembly inside a shared North American production system. For Canadian plants, parts makers and communities tied to auto manufacturing, the risk is not simply losing trade preferences. It is being structurally disadvantaged inside the agreement that was designed to protect continental trade.
A Rule That Rewrites What “North American” Means
CUSMA’s current auto regime is built around regional integration. Passenger vehicles and light trucks generally need 75% North American regional value content to receive preferential treatment, up from 62.5% under NAFTA. Producers must also meet separate requirements involving core parts, North American steel and aluminum purchases, and labour-value content tied to workers earning at least US$16 an hour. Those rules are demanding, but they largely treat qualifying production in Canada, Mexico and the United States as part of one continental system.
The Trump administration’s reported proposal would change that logic. It would raise the overall North American threshold to 82% and add a new requirement that 50% of the vehicle’s value be produced in the United States. Reuters reported that the proposal presented in U.S.-Mexico talks contained no specific mechanism for counting Canadian content toward that U.S. share. It remains a negotiating demand rather than settled law, and officials have not publicly explained the complete formula. Even so, the message to automakers is clear: a vehicle could contain overwhelmingly North American parts, be assembled in Ontario and still fail a new U.S.-specific test.
CUSMA Compliance Already Does Not Mean Zero Tariffs
The dispute is especially serious because Canadian vehicles are not currently enjoying completely tariff-free entry merely because they comply with CUSMA. Since April 2025, the United States has applied a 25% Section 232 tariff to the non-U.S. content of CUSMA-qualifying passenger vehicles and light trucks. An importer can document the U.S. value built into a Canadian vehicle and avoid the tariff on that portion, but the remaining non-U.S. value is still taxed. Canadian government estimates have placed the typical U.S. content of a Canadian-assembled vehicle at roughly 50%, implying an effective tariff near 12.5% in a representative case.
That creates two overlapping tests. CUSMA determines whether a vehicle qualifies as North American, while the Section 232 system separately rewards only the portion classified as U.S. content. A tougher 50% U.S.-content rule could merge those ideas more deeply into the trade pact, making national origin—not merely regional origin—the decisive factor. It could also leave manufacturers facing tariffs even after spending heavily to satisfy CUSMA’s existing requirements. For a plant manager deciding where to assign the next vehicle platform, compliance would no longer offer the certainty it once promised.
Canadian Plants Are Woven Into a Continental Supply Chain
The modern auto industry does not build vehicles within neat national borders. Engines, transmissions, electronics, stampings and other components move among specialized plants before final assembly. The Bank of Canada notes that many auto parts cross borders several times during manufacturing, which means a tariff can accumulate at different stages if exemptions do not apply. A Canadian-built vehicle may contain substantial U.S. content, while a vehicle assembled in Michigan may rely on Canadian metals, components or engineering. The nationality of the final assembly plant tells only part of the story.
That integration explains why the proposed rule could create costs on both sides of the border. Canada says more than 90% of its domestically made vehicles and about 60% of its auto parts are exported to the United States. In 2024, two-way automotive trade between the countries totalled roughly C$152 billion. A rule that penalizes Canadian assembly could therefore disrupt orders for U.S. suppliers feeding Canadian plants, not just Canadian factories. The worker loading a component in Ohio and the worker installing it in Ontario may depend on the same vehicle program, even though tariff policy treats their contributions differently.
Ontario Jobs Carry Most of the Immediate Risk
Canada’s auto sector directly supports more than 125,000 jobs and contributes about C$16.8 billion to national GDP, while the broader industry supports hundreds of thousands more through suppliers, dealerships and related services. Five major automakers—Stellantis, Ford, General Motors, Honda and Toyota—anchor the Canadian assembly base, supported by nearly 700 parts manufacturers. Most of that activity is concentrated in Ontario communities where a large plant supports tool-and-die shops, logistics firms, restaurants and municipal tax bases far beyond the assembly line.
The exposure to U.S. demand is unusually high. Statistics Canada found that, in 2023, U.S. demand accounted for 82% of Canadian motor-vehicle manufacturing output and 81% of the industry’s jobs. For motor-vehicle parts, the corresponding shares were 77% of output and 76% of jobs. The stress has already appeared in payroll data: from December 2024 to August 2025, employment at transportation-equipment manufacturers fell by 6,500, with most of the decline occurring among parts makers. A stricter content regime would land on an industry that has already been adjusting to tariffs, weaker orders and prolonged policy uncertainty.
Higher Costs Would Not Stop at the Canadian Border
Tariffs are collected from importers, but their economic burden can spread among automakers, suppliers, dealers and consumers. A 2025 Center for Automotive Research analysis estimated that the 25% auto and parts tariffs then under consideration could cost U.S. automakers about US$108 billion in one year, including roughly US$42 billion for Ford, General Motors and Stellantis. Its estimates placed the average tariff-related cost near US$5,000 for parts used in a vehicle and about US$8,600 for a fully imported vehicle, before later policy adjustments and company-specific offsets.
Actual retail effects depend on exchange rates, inventory, competition and how much cost manufacturers absorb. U.S. vehicle prices did not rise as sharply in 2025 as some early forecasts predicted, showing that headline tariff rates do not translate mechanically into sticker prices. Still, the pressure can appear in subtler ways: smaller discounts, fewer low-volume models, delayed redesigns or reduced equipment. A dealer may not add a line labelled “tariff” to the window sticker, but buyers can still encounter a higher monthly payment or less choice. Rules that force duplicate sourcing networks may also make North American production less efficient rather than simply more American.
Investment Can Move Before Any Final Deal Is Signed
Automakers plan factories and vehicle platforms years in advance, so uncertainty itself can influence decisions before a trade rule formally changes. Companies must estimate whether a model assembled in Canada will qualify for preferential access throughout its production cycle. If the answer depends on annual political reviews, changing tariff credits or a new U.S.-content formula, executives may favour a U.S. plant even when an Ontario facility is competitive. That is precisely why the definition of qualifying content matters as much as the tariff rate.
Recent decisions show how quickly production footprints can shift. Canada reduced tariff-remission quotas for General Motors and Stellantis in October 2025 after GM scaled back production in Oshawa and Ingersoll and Stellantis cancelled its Brampton production plan. At the same time, investment has not vanished entirely: GM announced C$63 million for next-generation truck production in Ontario in February 2026. The mixed picture matters. Canada still has skilled workers, existing plants and a deep supplier network, but every new allocation becomes a contest over long-term policy certainty. Once tooling and production are moved, reversing the decision can take years and billions of dollars.
The Auto Fight Is Becoming a Test of CUSMA Itself
The proposed auto rules are part of a broader effort by Washington to use the 2026 CUSMA review to reshape trade around U.S. manufacturing and economic-security priorities. U.S. trade officials have said they want stronger rules of origin, tighter safeguards against transshipment and measures aimed at preventing non-market economies from benefiting indirectly from the agreement. The United States and Mexico have already held bilateral rounds covering automotive rules, steel, aluminum and industrial origin requirements, while Canada was not included in the first Mexico City round where the 82% and 50% figures were reportedly presented.
That process has raised concerns that Canada could eventually receive a largely completed U.S.-Mexico framework rather than negotiate all major terms from the beginning. CUSMA’s review mechanism adds leverage but does not make July 1, 2026, an immediate expiry date. If all three governments do not agree to extend the pact, it remains in force and enters annual reviews, with possible expiration in 2036 if no later extension is reached. For automakers, however, a decade of recurring reviews could be almost as damaging as a sudden deadline because investment decisions depend on stable rules.
Canada Has Leverage, but No Easy Substitute for the U.S. Market
Ottawa’s strongest argument is that Canadian production strengthens rather than weakens U.S. manufacturing. Canadian-assembled vehicles contain substantial U.S. value, and Canadian plants buy components from suppliers across the Midwest. Canada can press for a genuinely regional calculation, seek credits for high-wage production, challenge discriminatory measures through CUSMA procedures and link tariff relief to continued investment on both sides of the border. It has also used retaliatory auto tariffs and performance-based remission programs to reward companies that preserve Canadian production.
Diversification is part of the response, but it cannot quickly replace the U.S. market. More than 90% of Canadian-made vehicles currently go south, and plants were designed around that demand. Canada’s 2026 auto strategy emphasizes retooling, domestic supply chains, next-generation vehicles and broader export markets, yet changing an export structure built over six decades will take time. The most realistic near-term objective is therefore not economic separation. It is preserving meaningful Canadian status inside North American production. The decisive question is whether CUSMA will continue to recognize Canada as a manufacturing partner—or merely as a foreign supplier granted limited access to the U.S. market.
