Trump’s Auto Tariffs Squeeze Suppliers Working on Thin Margins

Trump tariffs roiling the auto industry are hitting domestic and foreign supply chain middlemen, the cogs providing essential parts that keep production lines flowing.

Suppliers already operate on thin margins. If tariffs persist and there’s no help from their customers—which include both automakers and other suppliers—they could face an untenable choice: Breach long-term contracts or go bankrupt, companies and industry groups said.

Industry relief measures offered this week by President Donald Trump will help to some degree, but generally favor automakers.

“We’re still looking at input costs going up, and we’re looking at the whole supply chain looking at its ...