Edmunds forecasts that 1,331,787 new cars and trucks will be sold in the US in February for an estimated Seasonally Adjusted Annual Rate (SAAR) of 17.6 million. This reflects a 17 percent increase in sales from January 2017, but a 1 percent decrease from February 2016. Even though February is historically a slow sales month, it gets a bump from the President's Day holiday weekend when auto sales are usually 20 percent higher than an average February weekend.

"The holiday weekend is likely a contributing factor to strong sales in February, but we're also seeing signs that automakers are starting to be a bit more aggressive to move cars off the lot," said Jessica Caldwell, Edmunds executive director for industry analysis.

"Fleet sales were robust in February, and incentives are continuing to rise. While trucks and SUVs don't need as much help to find interested buyers, inventories of passenger cars have been building."

Analysts says that the US vehicle market is now topping out with little room for growth. That could spell lower profitability in a market that has been a big positive for OEMs and suppliers alike. Incentives on sales have risen in recent months.