Mr. Trump himself has threatened levies of 20 or 25 percent on foreign cars and implied that such penalties could help the United States negotiate better terms for trade with Mexico, Canada and the European Union. He and other administration officials say the United States is at a disadvantage and that better trade deals could ultimately add American jobs.

Yet auto companies have warned that erecting barriers to trade could be devastating for what is a highly globalized industry, in which cars and their parts are manufactured and shipped around the world.

Even cars with the highest percentages of American-made content regularly source a quarter to a third of their parts from abroad, industry statistics show. Last year, 52 percent of cars sold in the United States were manufactured in the country, with nearly half of those made by international firms like BMW, Daimler and Honda, according to the Center for Automotive Research, a nonprofit research organization.

[Read more about BMW’s ties to the United States.]

“We would argue that the supply chain allows us to remain competitive in this global market,” Jennifer Thomas, the vice president of federal government affairs at the Alliance of Automobile Manufacturers, which represents Ford, General Motors, Toyota and other global automakers, said at the hearing Thursday morning.

A study released Thursday by the Center for Automotive Research estimated that tariffs or quotas could cause the price of an average new vehicle sold in the United States to rise by $980 to $4,400, depending on the specifics of the policy.

The study, which was commissioned by the National Automobile Dealers Association, found that tariffs would increase American vehicle production. But the industry would still lose tens or hundreds of thousands of jobs over all as tariffs reduced employment at auto parts companies and higher prices discouraged consumers from buying cars, leading to lost jobs at dealerships.