DETROIT — Most major automakers reported U.S. sales gains last month as stronger employment figures and consumer confidence drove the auto industry to its best March in 16 years.

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 or peddle more cars 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.