Numbers that are down do not necessarily tell the whole story when it comes to both used-truck sales and new trailer orders. Starting with used trucks, thanks to scant inventory their sales “fell in all sales channels during May”, according to ACT Research Co. (ACT), which has reported sales volumes were down some 15% from April’s level.

But this is a short-term downer. “While used inventory continues to be tight, the industry should see some relief in supply and pricing as new truck sales improve,” said Steve Tam, vp- -commercial vehicle sector for ACT.

“Due to new truck buyers holding on to their equipment longer, used truck mileage continues to trend upward,” he added. “Vehicle age and mileage are expected to increase throughout 2011.”

ACT’s update on the market is contained in the latest release of its State of the Industry: U.S. Classes 3-8 Used Trucks report. ACT also reported that average miles for vehicles as well as prices in the used market have continued to increase.

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

ACT also has reported its latest findings on trailer sales. It found that total U.S. trailer net orders fell 9% during May. That marks the second consecutive monthly decline for the industry.

However, despite the decline, “trailer backlogs continued to grow, ending the month at 102,500 units, up 1% from April.” ACT’s trailer update is covered in its latest State of the Industry: U.S. Trailers, published on June 24.

The research firm also pointed out that trailer “build was up 87% from May 2010, while industry backlog was up 122% for the same time period.”

The bottom line on trailers is positive, though, as the order pattern appears in line with historical trends. “The decline in April net orders was actually in line with what would be expected from normal industry patterns,” explained Frank Maly, director CV Transportation Analysis & Research with ACT.

“The order board continues to appear solid, as supported by extremely low order cancellations,” he continued. “Fleets have taken their positions in OEMs’ production plans and, so far, are maintaining those commitments.”