The president wants to weaken limits on tailpipe pollution. Scientists say it’s driving climate change and taking human lives “every day.”

© Graham Dickie/The New York Times

The executive, Jim Farley, said President Trump’s tariff and auto policies would raise costs and could force the automaker to cut jobs.

Duties of 25 percent on steel and aluminum will flow through to car buyers, beer drinkers, home builders, oil drillers and other users of metal goods.

General Motors and a few other companies make as much as 40 percent of their North American cars and trucks in Canada and Mexico, leaving them vulnerable to tariffs.

Ties between the United States and Mexico have deepened over 30 years of free trade, creating both benefits and irritants.

The former New York congressman has little experience in environmental policy. He is expected to follow orders to weaken climate rules.

The electric car company run by Elon Musk is facing increasing competition, but investors have focused mostly on the prospects for Tesla’s self-driving technology.

States are using higher registration fees for electric cars to make up for declining fuel taxes, but some are punitive, environmentalists say. A federal tax could be coming.

The president wants to begin renegotiating a U.S. trade deal with Canada and Mexico earlier than a scheduled 2026 review, people familiar with his thinking said.

Automakers and even some Republicans may fight to preserve funds, and environmental activists will likely sue, but some experts said that some changes may not survive legal challenges.

For many residents, a set of wheels is an extension of their home, a key to their income or a source of priceless memories.

An investigation by the Federal Trade Commission determined that consumers had not been aware that the automaker was providing their driving information to data brokers.

Rules for a $7,500 tax break for electric vehicle purchases and leases recently changed, but more far-reaching changes are expected when President-elect Donald J. Trump takes office.

Gov. Gretchen Whitmer addressed the Detroit Auto Show, saying that tariffs should not be used “to punish our closest trading partners,” like Canada.

More car buyers are expected to eventually pick battery-powered cars and trucks as prices fall and technology improves, even if Biden-era incentives disappear.

The United Automobile Workers union asked a federal labor regulator to conduct an election at a factory Ford jointly owns with a South Korean battery company.

Turo, which investigators say was used to acquire the vehicles involved in the attack in New Orleans and explosion in Las Vegas, was emerging as an alternative car-rental service.

The electric-car company led by Elon Musk no longer has the market to itself. Investors are focusing on autonomous driving and other new technologies.

Sales of the company’s cars are flagging, but investors are focusing on the potential of autonomous driving and Mr. Musk’s ties to President-elect Donald J. Trump.