“We don’t think that the rate of growth of S.U.V.s will necessarily continue, but we do believe the shift to them is permanent,” said Mike Manley, head of Fiat Chrysler’s Jeep division.
Pickup trucks and S.U.V.s have accounted for about 62 percent of all new vehicles sold in the United States so far this year, compared with 57 percent in the first quarter of 2016, according to the research firm Autodata.
That extends a trend line that has inched upward since gasoline dropped below $3 a gallon in 2014.
The big American auto companies have been the greatest beneficiaries of the public’s appetite for high-riding, spacious S.U.V.s, which generally earn bigger profits for manufacturers than mainstream cars.
In March, more than 70 percent of the vehicles sold in the United States by General Motors and Ford Motor were trucks and S.U.V.s. The proportion was even higher, about 85 percent, for Fiat Chrysler.
All three Detroit automakers and their foreign rivals are working overtime to add new or updated sport utility vehicles to their lineups.
The trend worries environmentalists because S.U.V.s generally burn more gas than smaller cars, generating more of then harmful emissions believed to cause global warming.
Some automakers are also adding electric cars to their portfolios, but not in volumes equal to the proliferation of S.U.V.s.
But Mr. Trump’s move to cut back regulations — starting with his announcement last month that his administration would revisit the Obama administration’s fuel-economy standards — has given the industry less motivation to devote resources to electrified models or smaller, high-mileage passenger cars.
And while companies are committed to electric-car programs, their earnings are heavily dependent on feeding consumers’ appetite for new and improved S.U.V.s.
“The fact is these larger vehicles have been extraordinary profit centers, especially for the domestic manufacturers,” said Jack Gillis, public affairs director for the Consumer Federation of America, a nonprofit group that supports stringent fuel-economy rules.
As long as gas prices remain low, he said, the S.U.V. boom is likely to continue. But once prices begin to rise, consumers may become less enamored with the larger models.
“Economic conditions are going to drive improvements in fuel efficiency more than environmental considerations,” Mr. Gillis said. “Consumers will rethink their decision to buy a larger vehicle when it starts costing more to fill their gas tanks.”
For now, the market for S.U.V.s is seemingly growing by the day.
Some brands have been completely revitalized by the proliferation of S.U.V.s, which now come in sizes ranging from compact to extra-large.
The Buick division of General Motors, for example, is introducing a new version of its midsize Enclave S.U.V. at the New York show.
That follows the addition of two smaller sport utility models to the brand’s lineup. And where Buick was once synonymous with cushy sedans, it is now tilted heavily toward S.U.V.s.
“Up to three-quarters of our sales now are S.U.V.s,” said Duncan Aldred, head of the Buick division. “That’s how much Buick is on the track with the market.”
And though it is considered a midsize S.U.V., the Enclave is large enough to accommodate three rows of seats.
Mr. Aldred said the typical customers drawn to Buick S.U.V.s included families with young children who required considerable space and older drivers who appreciated the rugged capability and utility of a high-riding model.
He said that fuel economy was rarely a major consideration for consumers shopping for an S.U.V.
The existing Enclave model gets about 17 miles per gallon in combined city and highway driving, but the new version shown in New York is expected to improve upon that performance, once it is certified by federal regulators.
New technology, for example, allows for the engine to shut down and restart when the vehicle is idling, saving fuel. “The old perception that S.U.V.s are terrible on fuel economy is going away,” Mr. Aldred said.
Some of the newest S.U.V.s also cater to consumers interested in prestige, luxury, and, above all, comfort.
One such vehicle, Ford’s new Lincoln Navigator, is bigger and more powerful than the model it will replace, and is packed with features like a dial that selects from six modes set for varying weather conditions and terrain.
The new Navigator also has upgraded leather seats, plusher carpeting and running boards that appear automatically along the side to provide the driver and passengers a step for entering. The transmission is laid out like piano keys to be touched gently when putting the vehicle into park, drive or reverse.
“It is the most spacious and luxurious Lincoln S.U.V. yet, and will elevate family travel to what we call first class,” said Mark Fields, Ford’s chief executive.
Ford, which virtually created the full-size luxury S.U.V. segment 20 years ago with the Navigator, has been eclipsed recently by the popularity of G.M.’s Cadillac Escalade. The redesigned Navigator is intended to reclaim its place as the flagship for the Lincoln brand and to serve notice that Ford is no longer willing to settle for second place to its Detroit rival.
And while Ford is pushing luxury, other automakers are taking S.U.V.s to new levels of speed and performance.
Mercedes-Benz announced plans to produce powerful new versions of its big GL sport utility vehicle that can achieve as much as 500 horsepower.
Fiat Chrysler’s Jeep brand is going even further with its Grand Cherokee Trackhawk edition, which can generate more than 700 horsepower and hit a top speed of 180 miles per hour.