The used commercial truck market has generally been stable the past three months, notes an August report from NADA Used Car Guide. So far in 2016, auction prices have decreased less than 3% per month compared to nearly 5% per month in the second half of 2015.

"The sweet spot for pricing seems to be a 4-year-old truck with 400,000 to 500,000 miles," said Chris Visser, a senior analyst at the guide. “That type of truck has consistently brought pricing in the low to middle $40,000 range since January.

"That price range is attainable for many buyers, and the truck still has a year or two before a minor overhaul will be necessary." Visser's presentation on the August report is here.

The August report also says the market is less positive on the retail side. Three- to five-year-old trucks lost more of their value than anticipated because large groups of similar trucks brought average prices down. That group has lost 14% of its value so far this year, compared to 5% in the same period last year.

In general, NADA analysts state in the August Commercial Truck Guidelines that the market is back to its typical 3% to 5% monthly depreciation rate. Analysts point out the behavior is logical given current conditions. The freight environment remains moderately negative, but the domestic economy generally continues to show incremental upward growth.

NADA analysts do not expect any significant market changes through the end of the year. The conclusion is based on past presidential election cycles, which typically keeps industry from betting on large investments.