The U.S.-Canada trade war is creating a headache for auto-parts makers

A truck passes over the Peace Bridge between Canada and the United States, in Fort Erie, Ontario, on August 18, 2026. Cole Burston/AFP via Getty Images hide caption

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The U.S. and Canadian auto industries have been tightly woven together for decades. But the latest tariff flareup between the two countries may complicate that.

Think of that sticker on the windows of new cars breaking down how much of the vehicle's content comes from the U.S. and Canada. From a manufacturing point of view, content from both places has long been considered deeply intertwined.

But the U.S. and Canada failed to reach a new trade deal this summer, and the trade war between them has escalated quickly. In August, the U.S. enacted new tariffs on aluminum and steel, and President Trump has also threatened 50% tariffs on Canadian vehicles, auto parts and steel effective on Jan. 1. On Tuesday, Canada enacted retaliatory tariffs on a variety of U.S. goods — including on American steel and aluminum.

For major U.S. carmakers, analysts say, the tariffs introduce uncertainty as companies determine whether to adjust their supply chains in the long run, or to absorb new costs in the short term. But for the smaller businesses that supply those big companies with thousands of parts — think bolts, or the steel rods for steering wheels — the tariffs could spell bigger, more expensive trouble.

" It's really, really damaging to the industry and to the financials of the industry. It makes planning for things very difficult," says Dan Hearsch,  global co-leader of automotive and industrial at the consulting firm AlixPartners.

For these companies, he says, the new tariffs follow years of chaos — the aftermath of Covid supply chain shortages, the start-and-stop ramp up to making more electric vehicles, the need to grapple with pre-existing tariffs.