SANTA MONICA, Calif. -

December hasn’t traditionally been known as the year’s best month for new-vehicle sales, but based on the past two years — and the expected results for this December — there may be a “new normal” when it comes to the final month of the year.

In fact, it’s highly possible this month could be the strongest of 2011, according to Edmunds.com.

Bucking the trend spotted from 1991 to 2008 — when December was a top-three selling month only once (2004) — December was the best-selling month of 2010 and ranked No. 2 the year before, Edmunds pointed out.

That was quite a change from the preceding 18 years, when December’s average annual ranking was No. 8. But expect that shift to continue, analysts noted.

“December has certainly been a month to remember for dealers over the last two years,” stated Lacey Plache, chief economist at Edmunds.

“And with a substantial number of new-car buyers still coming back to the market after deferring their purchases this summer, dealers have plenty of reason to believe that this December will continue the trend,” Plache added. “Recent income growth, moderated inflation and improved consumer confidence are all combining to put consumers in a better position to spend.”

Of course, for December to be the year’s best month, it will have to eclipse figures from a year ago, when 1.15 million units were sold.

March currently ranks at the strongest month of 2011 with 1.25 million sales, and April is No. 2. During that month, there were 1.16 million vehicles sold.

Granted, a robust December isn’t out of the ordinary for luxury brands like BMW, Mercedes-BMW and Lexus, who often employ heavy incentives during the month and move out remaining current-year models.

“But only recently have some of the mainstream automakers joined the year-end party,” Edmunds noted, giving the example of Chevrolet.

December ranked as the No. 2 month for the Big 3 brand in 2010 and 2009. Compare that to 2006, when December was the seventh-best month for Chevy, and 2007, when it was eighth. Ford, Honda and Toyota showed comparable gains during this time frame, officials added.

The following list shows where December ranked each year from 2000 to 2010, according to Edmunds:

2010: First
2009: Second
2008: 10th
2007: Fifth
2006: Seventh
2005: Sixth
2004: Third
2003: Sixth
2002: Sixth
2001: 10th
2000: 10th