Continuing a trend witnessed almost every week since the middle of July, the $3.35 average price of gasoline this past week is another 2 cent decline, according to Black Book.

"Where some weeks the lower gasoline prices have not had an adverse effect the price change of most of the fuel-efficient models, each of the better fuel-efficient car segments had a larger weekly declining level this past week than the prior week. One example is within the Entry Level Cars. This past week, the change was -$48 as compared to the prior week of -$22," according to Ricky Beggs, VP and editorial director at Black Book.

According to Black Book, the level of change is also being driven by some seasonality reaction. This week, with an average segment change of -$74 for the cars, the change level has been increasing for the past three weeks. The Full-size Cars and the Premium Sporty Cars, going against the segment trend change, both showed better retention change levels week over week.

The truck segments overall change at -$64 is the largest weekly segment change over the past eight weeks. Only three segments had smaller declines this week than the prior week.

"For the first time in four weeks, the Luxury SUVs did not decline by at least -$100, this past week at -$91. Other improving segments were the Compact Crossovers going from -$51 two weeks ago to -$33 this past week and the truck-based Full-size SUVs had the smallest weekly decline of only -$14," Beggs said.

Another point of interest in change is the level of change this past week was at slightly larger levels than one year ago for both the cars and the trucks. In addition to the level of percentage change of -0.46 percent for cars and -0.45 percent for trucks, driven partially by the season of the year, the volume of change is at the highest volume of daily changes at 2148 per day, since the middle of this past summer for the week ending June 21, 2013.

View Ricky Beggs, "Beggs on the Market" video below: