New car and truck sales in Hamilton County hit a road bump in September as the number of titled vehicles failed to rise over last year for the first time in 2012.

Sales in September compared to the same month in 2011 were unchanged at 923 units, according to the Hamilton County Clerk's Office.

Still, for the year, new vehicle sales in the county are up 15.3 percent.

U.S. sales in September rose 13 percent from a year earlier to nearly 1.2 million, according to major automakers. If they stayed at that pace, they'd reach 14.9 million this year.

Low interest rates, aging vehicles that need to be replaced and appealing new models are the main drivers of this year's consistently strong sales, said Jessica Caldwell, an analyst for the Edmunds.com automotive website.

"That's a good combination to get people shopping again," Caldwell said.

Sales rose for most carmakers, led by big gains at Toyota, Honda and Volkswagen.

Jonathan Browning, chief executive of Volkswagen Group of America, said Tuesday that September VW sales rose 34.4 percent over last year with the Chattanooga-made Passat helping pace the hike. VW reported that 9,500 Passats were sold in September.

While Passat had its best September ever, sales of the midsize sedan were off from 10,900 in August.

Browning said in a conference call with analysts that the overall pace of new vehicle sales in the U.S. market is "pretty choppy."

He said he expects to see "some consumers hold off in the run up to the [presidential] election."

Industry sales across America are expected to continue up for the year, Browning said, but he doesn't foresee the numbers "setting the world alight."

Thad Narramore, new vehicle sales manager for Marshal Mize Ford, said September was "pretty good."

Looking ahead, Narramore said Ford Motor is forecasting that the redesigned Fusion midsize car will help drive sales up. He noted that the hybrid engine model of the Fusion will get 47 mpg.

"We think it will be a home run," Narramore said.

Corey Choate, general manager of Economy Honda, said his dealership had all-time record sales volume in September.

He questioned if new vehicles sales will undergo a downturn leading up to the presidential sweepstakes.

"I see nothing but blue skies ahead," Choate said.

VW reported that last month's U.S. sales were 36,663, its best September since 1972.

"We had continued strong performance from Passat," Browning said. The Passat recently came in first in Motor Trend's 2012-13 comparison test with other midsize vehicles, he said.

Concerning other models, VW reported its small sport utility vehicle Tiguan had its best September in the U.S. with 2,202 units sold.

The Beetle experienced its best September sales since 2003. The Jetta sedan achieved sales of 12,584 units in the month, according to VW.

VW's high-mileage, clean diesel TDI models accounted for 23.9 percent of all sales in September, according to the automaker.

GM said it sold 210,245 vehicles last month, and passenger cars led the way with a 29 percent gain.

But sales of the company's pickups, which are big profit producers, dropped by 20 percent during September. GM attributed the decrease partly to a reduction in sales to rental fleets, according to The Associated Press.

Nissan has been hurt as Toyota and Honda recover from last year's earthquake in Japan. The automaker sold 91,907 vehicles last month with its top-selling Altima accounting for 24,488.

Sentra sales jumped 15.3 percent to 9,345, while Pathfinder sales jumped 38.7 percent to 3,205.

The Associated Press contributed to this report.