The average value of used fleet vehicles increased 1.5% in August from the prior month and are now up 8.5% from a year ago, according to Tom Kontos, KAR Auction Services' chief economist.

Fleet lease vehicles were below used vehicles from manufacturers, which increased 3.2% on the month, but are up only 2% from a year ago. Vehicles from dealer consignors increased 1.9% from July and are up 0.6% from August 2017.

Overall wholesale values increased 1.4% to $11,049 and were up 0.9% on the year. Used cars were up 2.2% for the month, while truck values increased 1%, which indicates a "better supply-demand balance," Kontos said.

From a year ago, segments that typically have fleet vehicles, including midsize cars and midsize SUVs increased 7% to $12,460 and 5.6% to $20,932 respectively.