Net orders of class 5-7 vehicles rose to 19,700 in February for a 2 percent gain over the same month a year ago, according to the Start of the Industry report from ACT Research.

"After hitting a soft patch through the middle of 2014, medium-duty orders have been above year-ago results in five of the past six months, even against a tough year-ago February comparison," said Kenny Vieth, ACT's president and senior analyst. "Strong orders and below expectations build helped to boost the medium duty backlog-to-build ratio to 3.2 months, the highest reading in nearly five years."

Net orders can be a good measurement of the health of the medium-duty truck market because it presages truck sales.