But the sales growth rate appeared to be slowing as brisk SUV and truck sales barely offset falling car sales. Some automakers had to raise discounts on cars or peddle more of them to rental companies. That could mean better deals for car buyers down the road.
Overall, U.S. sales rose 3.2 percent to 1.59 million, the best March since 2000, according to Kelley Blue Book. But the growth was only about half of last year's 6 percent increase. Car sales dropped 6 percent, while SUVs and trucks were up 11 percent, according to Autodata Corp.
Ford, Honda, Fiat Chrysler, Nissan, Hyundai and General Motors all reported increases, largely driven by SUVs and trucks. But Toyota sales fell nearly 3 percent as rising SUV numbers couldn't overcome car sales that fell almost 10 percent. Toyota's Camry, the top-selling car in the U.S., saw sales drop 9 percent to just under 37,000.
The sales figures, coupled with Friday's announcement that U.S. employers added 215,000 jobs in March, showed that the economy remained healthy despite stock market turmoil. Unemployment rose slightly to 5 percent, but that was because the number of Americans looking for work has increased.
It all means that auto sales will continue to lead economic growth, said Mustafa Mohatarem, GM's chief economist. "We expect historically low interest rates, strong employment, rising wages and stable fuel prices to continue for the foreseeable future," he said.
Nissan sales were up 13 percent, hitting a record for any month in its history. At Fiat Chrysler and Ford, sales rose 8 percent, while they grew 0.9 percent at General Motors. Honda reported a 9 percent increase fueled largely by the all-new Civic compact, and SUVs. Hyundai sales rose just 0.4 percent, but it was enough to set a record for monthly sales.
Ford and Fiat Chrysler posted their best March numbers in a decade. General Motors, which has been cutting sales to rental car companies, said its retail sales to individual buyers rose 6 percent.
Volkswagen, still mired in an emissions cheating scandal, saw its sales tumble 10 percent.
Some analysts said there were troubling signs for automakers beneath the numbers. Last month had two more selling days than a year ago, and spending on discounts is on the rise.
Discounts, while good for new-car buyers, cut profits and hurt used car values. The auto pricing site TrueCar.com said automakers averaged just over $3,000 in discounts per vehicle in March, up more than 10 percent from a year ago.
The increase comes mainly because automakers are having trouble selling cars as the U.S. market shifts to trucks and SUVs, according to J.D. Power and Associates. Discounted cars can push down used car values so buyers have less to trade in, said Thomas King, a J.D. Power vice president.
"March car sales remain strong, but automakers are being forced to pull additional levers to sustain those sales, like selling more cars to fleets, enriching incentives and using leasing and extended-term loans to keep monthly payments within consumers' budgets," said Autotrader.com senior analyst Michelle Krebs.
Mark LaNeve, Ford's U.S. sales chief, said he's seeing increased car discounts because of the market shift toward SUVs and trucks, but "not anything that would be alarming."
If car inventories start to rise, automakers will offer more discounts to sell them, said Tom Libby, manager of industry analysis for the IHS Automotive consulting firm. "That will offer opportunities for consumers in the short-term," he said. But in the long term, companies will follow the trends and produce more SUVs and fewer cars, he said.
Automakers released their U.S. sales for March on Friday. These were the top selling cars and trucks, the number sold and the percent change from March of 2015.
Ford F-Series 73,884 +9.1
Chevrolet Silverado 47,966 +6.1
Ram Pickup 44,874 +7.9
Toyota Camry 36,991 -9.3
Nissan Altima 34,856 +8.9
Honda Civic 32,855 +21.8
Toyota Corolla 32,556 -8.4
Honda Accord 30,523 +17.3
Ford Fusion 29,675 +2.2
Toyota RAV4 29,045 +15.1
Source: Autodata Corp.