When the history of the contemporary auto industry is written, 2014 will go down as a year of contrasts. Deluged by safety recalls, auto manufacturers faced the ire of regulators and consumers. Yet, buyers did not stay away and instead gave the American auto industry its best sales year in nearly a decade.

The result, announced on Monday, was a crushing sales success: Nearly one million more vehicles were sold in the United States last year than in 2013. According to the tracking company Autodata, 16.5 million new autos hit the streets the highest number since the record of 16.94 million in the prerecession days of 2006.

Analysts cited a host of reasons for the growth: a rebounding economy, increasing consumer confidence, falling gas prices and cheap leases all helped unleash pent-up demand that sent Americans into dealers showrooms last year.

Domestically, Fiat Chrysler soared to a 16 percent increase in sales last year compared with 2013. The company sold more than two million vehicles in the United States, and its Jeep brand set a record for its best sales year.

General Motors, engulfed for much of the year by the gravest safety crisis in its history, sold nearly three million vehicles, up 5 percent from 2013, with seven of its vehicles setting records for annual sales. Those vehicles included both G.M.s smaller cars like the Sonic and Spark, as well as its sport utility vehicles like the Buick Enclave and its smaller sibling, the Encore.

Akshay Anand, an analyst for Kelley Blue Book, said that 2014 blew away anyone's expectations

With low gas prices and an improving economy putting more money in people's pockets, Americans were ready to spend on new vehicles. Utility vehicle and luxury segment really benefited, as consumers were willing to spend more, Mr. Anand said. America loves its S.U.V.s and trucks

Buyers flocked to smaller S.U.V.s like the new Jeep Cherokee, which sold nearly 180,000 in its first full year. Honda's CR-V was up 10 percent for the year, and Toyota's RAV4 rose 23 percent.

But 2014 was good for the largest vehicles, too. General Motors benefited from the public's return to its embrace of full-size S.U.V.s. The Chevy Tahoe rose 18 percent, while the GMC Yukon surged 48 percent for the year.

Michelle Krebs, senior analyst for AutoTrader.com, said G.M. ended the year on a very high note, particularly in light of a year of really bad recall news.

The exception among domestic manufacturers was Ford Motor, which had warned for months that it saw 2014 as a year of transition.

In the end, the company's sales were down slightly for the year, and the Ford brand posted a yearly drop of 1.1 percent on volume of 2.39 million vehicles, down nearly 26,000 from 2013. Its car sales fell 4 percent for the year; only two models, the Mustang and Fusion, posted gains.

Ford's truck sales declined about 1 percent. That dip was largely because of Ford's gamble that a striking redesign of its F-150 long the best-selling vehicle of any kind in the United States would be worth it. The company sold about 10,000 fewer F-Series pickups in 2014, as its Dearborn plant shut down for weeks to retool for the mostly aluminum-bodied new truck, and some buyers sat on the fence.

Ford is making a big bet on the F-150, which is only now starting to reach buyers. Ms. Krebs, the analyst, said that Ford could call 2014 a transition year, but she added, The real test comes this year, when the new F-150 is on the market in full force.

Toyota and Nissan also reported strong sales in the United States. Toyota rose 6 percent for 2014, and Nissan increased 11 percent. Honda's sales rose about 1 percent for the year.

Already, the industry is looking ahead to what 2015 could bring, and whether last years robust sales will continue.

Christopher Hopson, director of light vehicle forecasting at IHS Automotive, said he anticipated the final push of 2014 could reflect the momentum expected for 2015, and is forecasting the industry could sell 16.9 million vehicles this year on par with the high of 16.94 million sold in 2006.

Others urged caution. Ms. Krebs said the equation for 2015 would be different for automakers in one important way: More used cars are finally expected to come onto the market. That would put more pressure on new-car dealers to find ways to persuade buyers to choose a new vehicle instead of a good used one, she said.

We're going to have a lot of supply, she added, and the automakers will have to deal with it.