While current production is at strong levels, FTR Associates said most demand is being created by the onset of new EPA-compliant 2010 engines.

In the April North American Commercial Truck and Trailer Outlook flash update, FTR indicated that fleets are taking advantage of build slots for power units with pre-2010 EPA engines while they are still available. This is pulling demand forward from the second half of the year, FTR said.

"The current production numbers will not be sustained once the remaining stock of pre-2010 engines is exhausted," said Eric Starks, president of FTR Associates. "The basic issue affecting overall 2010 demand - the still large inventory of underutilized and idle trucks -- remains. Pulling ahead orders now to avoid 2010 engine technology will be at the expense of second half production."