Depreciation is picking up across the board for both cars and trucks; however, it is especially the case for trucks, with the average depreciation change last week falling 0.46 percent, the largest drop for trucks in nearly a year indicating that the fall price declines might finally be in full gear, according to the weekly "Used Car Market Report" from Black Book, 

“It’s beginning to feel like fall and along with the decreasing temperatures outside, we are seeing decreasing values across all our segments,” said Anil Goyal, vice president of Automotive Valuation and Analytics at Black Book.

Overall, the volume-weighted car values decreased by 0.51 percent for the week ending Sept. 22. This is the highest depreciation rate seen since the third week of July, according to Black Book. Segments that suffered the largest depreciation last week include Upper Mid-Size Car, Entry Level Car and Full-Size Car with declines of minus 0.89 percent,  minus 0.88 percent, and minus 0.75 percent respectively.

Overall, the volume-weighted truck values decreased by 0.46 percent this past week. This is the largest truck segment depreciation rate seen since October 2014, according to Black Book. Compact SUV, Full-Size Cargo Van and Full-Size Passenger Vans saw depreciation greater than 1 percent. Mid-Size SUV, Mini Van Cargo and Mini Van Passenger experienced only small decreases in value.