Santa Monica and Irvine, Calif. - TrueCar.com and Kelley Blue Book both released their numbers on transaction pricing for December 2013, and while the two usually have similar results, for this month there is a huge gap.

TrueCar.com noted that the average transaction price (ATP) for light vehicles in the U.S. was $30,786 in December 2013, down $201 (-0.6 percent) from December 2012; and down $35 (-0.1 percent) from November 2013. Kelley Blue Book's numbers, however, showed that new-car transaction prices increased an average of $197 per month-over-month in December 2013, with the estimated average transaction price for light vehicles in the United States sitting at $32,890, up 0.6 percent, and down $159 (0.5 percent) year-over-year.

"Incentives, as a percentage of transaction price, are up for several brands - a trend worth keeping an eye on," said Larry Dominique, executive vice president, TrueCar, and president, ALG. "Chrysler is one automaker that appears to buck this trend, showing positive momentum with a key product launch imminent."

"Along with solid new-car sales, average transaction prices on new vehicles continue to strengthen this year," said Alec Gutierrez, senior analyst, Kelley Blue Book. "Honda average transaction prices remain flat from last month, but are up a respectable 2.5 percent year-over-year with strong Acura prices (up 10.8 percent year-over-year), primarily due to the new MDX. Chrysler also revealed a solid increase year-over-year, thanks to better performance from its Jeep lineup. Jeep alone was up 2.5 percent year-over-year on the Grand Cherokee and Wrangler, while the Chrysler brand climbed 2.2 percent from this time last year due to a lower mix of its 200 model."