Reported volumes of used Classes 3-8 truck sales slipped back into negative territory in October, after enjoying a recovery in September. Scarce inventory and sustained demand may be the cause.

The update on the used market was reported in the latest release of the State of the Industry: U.S. Classes 3-8 Used Trucks, published by ACT Research.

"Despite continued improvement on the new truck sales side, along with repeated assurances that carriers are not expanding their fleets, expected trade-ins have yet to provide any relief to the growing equipment shortage," said Steve Tam, vice president-commercial vehicle sector with ACT. "Special programs in the late 1990s and early 2000s that lured traditional used truck buyers into new truck purchases are no longer in effect, so the demand for used equipment continues to expand," he added.

Last week, Truckinginfo reported sales figures published by Polk showing used commercial vehicle registrations for Classes 3-8 in the U.S. during the first three quarters of 2011 reached record levels at 649,900 units, surpassing the previous record for the first nine months of a calendar year by 23.9%.

The report from ACT provides data on the average used price for the top-selling Class 8 model for each of the major truck OEM's - Freightliner (Daimler); Kenworth and Peterbilt (Paccar); International (Navistar); and Volvo and Mack (Volvo).