25% import taxes on engines, gearboxes and other critical auto parts have been effective in the United States, increasing pressure on the industry to find its own way through a series of policy changes.

The new tariffs come days after Donald Trump mitigated measures to address corporate concerns, but did not eliminate the measure.

The U.S. president said the new tariffs, along with the 25% import tax on cars that came into effect last month, are intended to drive automakers to do more manufacturing in the U.S.

But analysts say any immediate expansion in the U.S. could come at the cost of production elsewhere, while also leading to higher business costs and ultimately higher prices for customers.

Currently, the company has avoided pain as concerns about rising prices have caused sales surges.

GM and Ford reported this week that double-digit sales growth continued in April.

But GM also warned that new fees this year are as high as $5 billion (£3.7 billion) due to tariffs, including around $20 billion in South Korean car charges and exports to the United States.

Executives said they now expect prices to rise about 1% instead of previous forecasts.

Amid the signs of turmoil, other auto companies, including Jeep, Fiat and Chrysler manufacturers, have withdrawn financial guidance for the coming year, citing liquidity in the situation.

"We are still affected by extreme uncertainty," Stelantis chief financial officer Doug Ostermann told analysts this week.

Nearly half of the vehicles sold in the United States last year were imported from areas outside the country.

When Trump announced plans for crashes and certain auto parts hit 25% tariffs in March, the announcement came under the circumstances of other large tariffs, which triggered a shock wave across the industry, causing warnings about higher prices and risks for production and sales risks.

Since then, the president has eased his policies, especially on key parts of Mexico and Canada, due to decades of free trade between the three countries.

For now, the parts of Mexico and Canada that are in compliance with the Free Trade Agreement will retain their responsibilities. Officials initially described it as temporary, but after customs directives issued this week, analysts said it seems that it can be held on now.

Trump also signed measures this week to cover up the company's exemption from multiple tariffs on the same item, while building a two-year system that automakers can use to reduce the responsibilities paid for parts imported from other countries and to use cars assembled in the U.S.

The government has also said companies importing cars made in Canada and Mexico will not impose tariffs on content made in the United States.

"The changes that have happened in recent days will make things easier...but even so, the market is still a huge change," said Stephanie Brinley, lead automotive analyst at S&P Global Mobility. "It's still a huge tariff."

Executives at some companies say they are exploring ways to increase U.S. production to reduce new costs.

GM said it has expanded its Fort Wayne, Indiana plant by 50,000 due to tariffs. This week, it also said it would reduce Canadian output.

Mercedes also said it has the flexibility to expand its plant in Alabama.

Art Wheaton, director of labor research at Cornell University, said the U.S. may see more such announcements in the coming months, but given the importance of the investment and the situation is changing, he does not want to see a new factory be completed anytime soon.

“If I were to make a multi-billion dollar decision… I wouldn’t do that in a volatile market,” he said.

The government said it is conducting trade agreements with major countries in the industry, including South Korea and Japan.

Wheaton said Trump could also change his policies if there were signs of economic losses.

"Everything is good now," he said. "I don't think the full impact of these tariffs has been met yet."