For the second straight month in May’s preliminary net order reading, North American Class 5-8 net orders experienced a sequential decline. Orders fell 11% from April to 38,100 units.

“Differentiating May from April is the fact that all of the month-over-month decline in May resulted from a dramatic slowing in heavy duty order intake,” said Steve Tam, Vice President at ACT Research. “Despite the month-over-month decline, May’s combined HD and MD volume bested May 2016 by 20%.”

Seasonal adjustment in May, which typically kicks off the slowdown in the order season, bumped the seasonally adjusted tally up slightly from actual to 40,500 units.

At 16,800 units, the preliminary read on May’s NA Class 8 orders was the lowest in the past seven months, shrinking 30% month-over-month, but advancing 18% year-over-year.

“While the magnitude of the decline is greater than expected, the timing is spot on,” said Tam. “May is typically the time of the year when order intake drops below average,” he noted.

Preliminarily, NA Class 5-7 orders jumped 13% from April and 22% from year-ago May, to 21,200 units.

“Medium-duty orders saw a resurgence, though not quite to the level they enjoyed in the December to March time period,” said Tam. “As May tends to be a below average order month, seasonal adjustment boosts the month’s net order volume, which rises to 22,400 units,” he concluded.