New-vehicle sales for 2017 should reach 17.1 million, which would make 2017 the fourth-highest year on record and signals continuing robust health in the automotive industry, according to Kelley Blue Book.

The 17.1 million is a 2% decrease from last year, according to data from KBB. For 2018, Cox Automotive, Kelley Blue Book's parent company, forecasts new-car sales at 16.7 million units for the year.

Closing out the year in December, new-vehicle sales are expected to decline 7% year-over-year to 1.57 million units, resulting in an estimated 17.6 million seasonally adjusted annual rate (SAAR), according to Kelley Blue Book. The SAAR is down from 18.1 million in December of 2016 and up from 17.3 million in November.

"December should be the biggest sales month of the year, and despite our expectations for significant year-over-year declines, the projected SAAR of 17.6 million would be the third highest of the year," said Tim Fleming, analyst for Kelley Blue Book. "It's also important to remember that December 2016 was the strongest month in nearly 15 years, fueled by heavy incentives and year-end sales objectives."

Most automakers are expected to report negative sales growth for December. Ford is on track to have one of the better months by gaining nearly 1% of market share. Ford SUVs may lead the way and could grow by as much as 10%.

Full-size trucks should be the second-largest segment in the industry in December with market share as a high as 14%. Mid-size cars will have another rough month, and market share could drop as much as 1.5%. Overall market share for cars could end the year under 36%, which is down from 39.2% in 2016.