The Class 8 market saw quite a boost last month, with net orders up 91 percent from April 2009
, according to ACT Research.

In the latest release of the State of the Industry: Classes 5-8 Vehicles, ACT said net orders for heavy-duty vehicles have been strengthening every month. New orders were spread over the next three quarters, suggesting that companies are beginning to place orders for new EPA 2010 emissions-compliant equipment.

For medium-duty Classes 5-7 equipment, net orders increased by 39 percent in April, compared to the year-ago month. However, with continued weakness in the residential housing market and tightening state budgets, the medium-duty sector has not shown the same level of rebound as the heavy-duty sector, ACT said.

"From top to bottom, April was a healthy month for the Class 8 segment, at least in relative terms," said Kenny Vieth, partner and senior analyst with ACT. "Orders were above expectations, backlogs rose and retail sales remained elevated. If orders surprise on the high side again in May, it could have upside implications for our forecasts for the remainder of 2010 and 2011."