The graph below traces new truck sales and average retail used pricing for all sleeper tractors under 1,000,000 miles. We consider used truck pricing a reliable proxy for demand, since other measures such as total sales reported or sales per dealership are subject to external variables which reduce their precision.
As you can see, the correlation between new sales and used pricing is generally strong, with sales and pricing largely mirroring each other directionally. For the entire graph, the actual correlation is a relatively strong 0.791. For the post-recovery period (starting in January, 2010), that number jumps up to 0.896.
New sales and used pricing both took a dip in late 2011. On the new side, this shift was likely due in part to the December expiration of tax incentives that encouraged purchases of new trucks. On the used side, there was probably increased pushback from buyers reluctant to pay high prices for trucks with historically high mileage. A price ceiling of sorts appears to have formed in this period.
However, this trend reversed in early 2012. Both new sales and used pricing are back on the uptick. This movement is at odds with the recent sustained downward trend in new truck orders. Orders and sales are typically not closely correlated, due to ad-hoc delivery schedules and fluctuating dealer inventory levels. As such, the downward trend in orders should not be viewed in a vacuum. Orders are a critical measure of demand, but they should be considered alongside sales and used pricing to gain a more complete picture.