SOUTHFIELD, Mich. — U.S. consumers, who are more confident than they have been in eight months, were lured to auto showrooms by holiday discounts and may have pushed car sales to the second-fastest pace in more than two years.

“From Thanksgiving on, they’ve been very aggressive,” Bob Tasca, whose family owns Ford, Lincoln, Mazda and Volvo dealerships in Rhode Island and Massachusetts, said of automaker discounts. “We’ve had the best deals of the year.”

Tasca said he expects his best December in five years.

Light-vehicle sales in December, set for release today, may have run at a 13.4 million seasonally adjusted annual rate, the average estimate of 13 analysts surveyed by Bloomberg, up from the 12.4 million pace a year earlier. While the rate may trail the 13.6 million seasonally adjusted pace in November — typically a slow sales month — the number of units sold increased in December, according to the average of five estimates.

Consumer confidence reached an eight-month high in December, according to the Conference Board, as carmakers aired holiday ads and continued promotions begun in late November, which led to the highest seasonally adjusted rate of the year.

Tasca, whose dealerships sell about 400 cars and trucks a month, credits aggressive marketing by Ford and others for making December the top month of 2011.

Ford brand sales for the year were above 2 million for the first time since 2007, the Dearborn, Mich.-based company said last week.

“The carmakers haven’t put out many new deals since the end of November; they just advertised them heavily,” said Ivan Drury, a senior analyst with Edmunds.com, a consumer-research website based in Santa Monica, Calif. “If you combine consumer optimism with the fact that some people have older cars and need to replace them, sales are going to go up.”

Carmakers used the holiday season to discount remaining 2011 models, boosting those incentives by 10 percent from last month, said Jesse Toprak, vice president of industry trends for Truecar Inc., another auto website based in Santa Monica.