DETROIT — The U.S. auto industry's historic growth streak may be ending, but demand for new vehicles — especially SUVs — remains healthy as the new year begins.

U.S. auto sales are expected to fall two per cent to 17.1 million in 2017, according to Kelley Blue Book. That would be the first year-over-year decline since 2009, ending an unprecedented seven-year expansion.

General Motors (GM.N), Toyota (TM.N) and Ford (F.N) all reported one-per-cent declines in sales last year compared to 2016. Fiat Chrysler's (FCAU.N) sales fell eight per cent. Honda's (HMC.N) sales were flat, while Nissan's (NSANY.PK) rose two per cent. Volkswagen (VLKAY.PK) brand sales rose five per cent.

While sales are likely to fall short of 2016's record of 17.55 million, 2017 is still expected to be the fourth-best sales year in U.S. history.

Analysts think sales will fall a bit further this year. While low unemployment and rising consumer confidence are expected to boost demand, rising interest rates could make it more expensive for people to finance new vehicles.

"That's real money to consumers," said Charlie Chesbrough, a senior economist with Cox Automotive, which owns AutoTrader.com and other car-buying sites.

Vehicles are also becoming more durable so many consumers aren't buying new ones, which further puts a drag on sales. The average age of vehicles on the road has climbed to 11.6 years, up from 8.8 years in 1998.

The growing popularity of leasing will have a big impact on 2018 sales. Almost one-third of new vehicle sales were leases in 2015, and many of those 4 million lessees will be trading in their vehicles for new ones, according to the car buying site Edmunds.com. (Edmunds regularly provides content, including automotive tips and reviews, for distribution by The Associated Press.)

But leasing also has a downside for automakers, since the influx of late-model used cars returning to the market will cut into sales of new vehicles.

Tax cuts also could be a mixed blessing. They will likely stimulate demand, particularly for commercial trucks and vans. But the more the economy grows, the more likely it is that the government will raise interest rates, Chesbrough said.

Here are more details of December and 2017 sales:

WINNERS AND LOSERS: Ford's F-Series pickup truck remained the bestselling vehicle in the U.S. in 2017, a title it has now held for 36 years. Ford sold 896,764 F-Series trucks in the U.S. last year, or nearly two trucks every minute, partly because of post-hurricane demand in Texas and Florida. Low gas prices and other factors had buyers ditching cars for SUVs at a fast clip; sales of the GMC Acadia SUV jumped 26 per cent, while sales of the Nissan Rogue SUV jumped 22 per cent to more than 400,000. Car-heavy brands like Chrysler, Dodge and Fiat all saw their sales drop by double-digit percentages. Toyota Prius hybrid sales plummeted 20.5 per cent.

LUXURY CROWN: Mercedes-Benz's sales fell one per cent to 337,246, but that was still enough to make it the top-selling luxury brand in the U.S. for the second straight year. BMW eked out a second-place finish just ahead of Lexus. But some luxury brands struggled. Cadillac and Lexus both saw their sales drop 8 per cent last year; Lincoln sales plummeted 17 per cent in December. Mark LaNeve, Ford's U.S. sales chief, said mainstream brands are getting so luxurious that many buyers don't feel the need to step up to a luxury label.

PILING ON THE DEALS: New vehicle prices hit a record last year, averaging US$36,113 as buyers bought bigger SUVs and added more safety and infotainment features, Kelley Blue Book said. At the same time, automakers piled on deals in order to juice sales and hang on to their market share. Chevrolet was offering $11,000 off a 2017 Silverado pickup as part of an employee-pricing promotion in December. Automakers spent an average of US$4,302 per vehicle in incentives last month, passing the previous record set in November, according to the consulting firm J.D. Power. Analysts expect a pullback in incentive spending this year as automakers cut inventory. But there will still be good deals, especially on slow-selling vehicles like midsize sedans.

DECEMBER DIP: No one was expecting U.S. auto sales to top December 2016, which was the best single month in 15 years. Ford's sales were up one per cent last month as its new large SUVs hit the market, but most automakers saw declines. Fiat Chrysler's sales fell 11 per cent for the month, while Toyota's sales dropped eight per cent and Nissan's sales were down 9.5 per cent. GM's sales fell three per cent. Volkswagen's dropped 19 per cent.