The move was expected to affect a small share of car manufacturing in China, where 28 million vehicles were produced in 2016. China has dozens of small-scale automakers — some producing just a few hundred cars a year — and the central government has tried to consolidate its auto industry, a factor that most likely also played a role in the suspension. Model versions — for example, different combinations of an engine and transmission — are constantly being deregistered.

Cui Dongshu, the secretary general of the China Passenger Car Association, said that the ban would affect at most 1 percent of the Chinese market. But the government’s decision to cite fuel economy in the deregistration of so many versions at the same time is nonetheless a signal of the government’s commitment to fuel economy.

The country, which for years prioritized economic growth over environmental protection and now produces more than a quarter of the world’s human-caused greenhouse gases, has emerged as an unlikely bastion of climate action after President Trump’s rejection of the Paris climate agreement.

Chinese leaders are under intense pressure to rein in dangerous air pollution, a hot-button issue in China, where thick smog has at times forced schools and businesses to temporarily shut down. Late last month, China said it was going ahead with plans to create the world’s largest carbon market, giving Chinese power companies a financial incentive to operate more cleanly.

“They’re sending a signal to everybody — that this is for real,” said Michael Dunne, president of Dunne Automotive, a Hong Kong-based consultancy on China’s clean car market. “This shows their emissions standards have teeth.”