admin 
The index fell to 205.9 in September, down 0.6% from a year earlier and 1.1% from August after adjustments for vehicle mix, mileage, and seasonality. Non-adjusted wholesale prices declined 1.2% year over year and 1.3% month over month.
Cox Automotive also lowered its year-end forecast, now expecting the Manheim Used Vehicle Value Index to finish 2026 up approximately 0.2% year over year, compared with the 2% increase projected in July.
“We are in the weakest season for wholesale valuations, and as September closed, depreciation was steeper than we typically see this time of year,” said Jeremy Robb, chief economist at Cox Automotive.
Fuel Costs and Interest Rates Pressure Vehicle Values
Following stronger-than-normal appreciation during the first half of 2026, wholesale values weakened in the third quarter amid higher fuel costs, rising interest rates, and broader economic pressures.
Diesel-powered vehicles accounted for just over 3% of wholesale inventory, but days’ supply climbed to 39 days, 27% higher than a year ago. Cox Automotive reported that record-high diesel prices contributed to weaker valuations.
Large pickups and SUVs also experienced declining demand and values as fuel costs increased. Meanwhile, older, more affordable vehicles showed greater resilience, with smaller declines in value.
Electric vehicles moved in the opposite direction. The Manheim EV Index increased 4.3% year over year and 0.6% from August, while the non-EV index declined 1.6% year over year.
Off-Lease Supply and EV Remarketing Volumes Increase
Wholesale EV sales at Manheim increased 22% from the second quarter and 45% from a year earlier. EVs represented a record 4.9% of Manheim transactions during the third quarter, compared with 3.9% in the second quarter.
Off-lease EV supply is also increasing. EVs accounted for approximately 10% of off-lease supply during the first half of 2026 and are expected to represent about 16% during the second half, potentially reaching 19% by summer 2027.
Overall off-lease vehicle supply is recovering from its first-quarter low. Monthly volumes are increasing from approximately 190,000 units in the first half of 2026 to an estimated 220,000 units in the second half.
Cox Automotive expects the continued increase in off-lease supply to contribute to approximately 3% growth in wholesale volume in 2027.
Cox Automotive Updates Used-Vehicle Market Forecast
Cox Automotive raised its 2026 total used-vehicle sales forecast slightly to 38.5 million units, up from its previous estimate of 38.4 million. Retail used-vehicle sales are expected to reach 20.5 million units, while certified pre-owned sales are projected to total 2.6 million units, down 1.8% year over year.
Total wholesale volume is forecast at approximately 11.8 million units in 2026, an increase of less than 1% from 2025. A projected 23% increase in off-lease volume and 5% increase in rental volume are expected to be partially offset by a 3% decline in dealer-sourced units.
Looking ahead, Cox Automotive is monitoring rising interest rates, declining consumer sentiment, and fuel costs as potential pressures on wholesale values. Recovering fleet demand and an aging U.S. vehicle population could provide some support.
For additional data and analysis, see the Q3 2026 Manheim Used Vehicle Value Index Report.
