Preliminary orders of Class 4-8 trucks increased in June, with Class 8 trucks crossing the 40,000-unit level for the fourth time in six months and medium-duty orders increasing to 26,400 units in a month that's typically weak for Class 5-7 vehicles, according to ACT Research.

Class 8 net orders reached 42,200 units, which represents a 133% increase from June of 2017. The company will publish final numbers later this month.

"As June is typically a weak order month, the robust actual order volume boosts June's seasonally adjusted volume to the best of the cycle and second best of all time at 48,200 units," said Kenny Vieth, ACT president and senior analyst. "Through year-to-date June, Class 8 orders have been booked at a 492,000 seasonally adjusted annual rate."

Medium-duty orders continued at a "solid" pace in June, with a 23% increase from year-ago levels. Orders were a bit lower than the monthly average for the first quarter. Manufacturers have reported booked business through June that has orders on track to reach 320,000 for the year on a seasonally adjusted basis.

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