With vehicle production and inventories recovering for Toyota Motor Corp. and Honda Motor Co., the fourth quarter may be the year's strongest, Al Castignetti, Nissan Motor Co.'s vice president of U.S. sales, said in an Oct. 3 telephone interview.

"People who have been sitting on the fence are likely to get back in the market," he said.

While the U.S. is "shaking off" the first-half drags, it faces risks from events at home and overseas, Feroli said.

The debt crisis in Europe will "likely slow the economy to the edge of recession by early 2012," Andrew Tilton, senior economist at Goldman Sachs in New York, said in note last week to clients. He sees growth falling to a half percent in the first quarter of 2012.

A mild recession in the euro zone could shave as much as a half percentage point off U.S. expansion, said Nariman Behravesh, chief economist in Lexington, Massachusetts, at IHS Inc. The direct effect on trade likely would be small, he said. U.S. exports to the euro area were equivalent to less than 2 percent of GDP last year.

Greater consequences could come from the financial links between the two economies and the impact of the crisis on the U.S. stock market and general confidence.

"Europe is so large and so closely integrated with the U.S. and world economies that a severe crisis in Europe could cause significant damage by undermining confidence and weakening demand," Treasury Secretary Timothy F. Geithner said Oct. 6 in testimony to the Senate Banking Committee. That would pose a "significant risk to global recovery."

Policy makers in Europe aren't the only officials on the spot, according to Diane Swonk, chief economist at Mesirow Financial Inc. in Chicago. Authorities in the U.S. also need to act, she said. If a Congressional supercommittee can't come up with the more than $1 trillion in budget savings required by November, "that further undermines confidence in our own government," she said.

The U.S. also faces a big fiscal squeeze in 2012 from the scheduled expiration in December of a payroll-tax cut, extended unemployment benefits and a business-tax credit.

"We have a very big tightening on track for next year," Feroli said. He put the amounts involved at about $350 billion, or the equivalent of about 2 percent of GDP.