The number of commercial vehicles in GVW Classes 4-8 registered this year through August fell 4.2%, mostly due to a steep decline in Class 8 over-the-road trucks, IHS Automotive has reported.

Registrations of Class 8 vehicles are 17.1% lower than a year ago, while registrations of Class 7 vocational trucks are down only 0.6%, according to research presented by IHS Markit at the Automotive Aftermarket Products Expo.

Freightliner leads the market for Classes 4-8 with 27% of registrations from January to August.

IHS has also analyzed light-duty registrations and found that Class 1 — a segment that would include compact vans and mid-size pickups — has the lowest volume of vehicles registered to a business with a 24% share. Almost 96% of vehicles in Classes 7 to 8 are registered to a business.

"Traditionally, the larger trucks have a single purpose — for work applications — versus the smaller trucks, which are used for both personal and business needs," said Gary Meteer, director of commercial vehicle solutions at IHS Markit. "As we work our way up the weight [GVW] scale, the business use gets larger."

New vehicle registrations among fleets operating more than 500 vehicles have declined, resulting in the decline of tractor-trailer trucks versus the same period in 2015, according to IHS.

"These large fleets have been in a replacement cycle for the past five years, and large fleets have accounted for more than 50% of GVW 8 new registrations during this period," Meteer said. "Some of this year’s slowing may be the result of uncertainty in the demand for goods with the general slowing of the economic growth in the most recent quarters."

When comparing new registrations against vehicles in operation, businesses with more than 500 vehicles have 43% share of new registrations, while only representing 22% of vehicles in operation. Class 6 vehicles are leading new registrations with a 54% share, while Classes 7 and 8 have the highest share (24%) of vehicles in operation.

Diesel-powered engines continue to dominate newly registered commercial vehicles. Overall diesel share is influenced by the availability of diesel-powered engines within each GVW range. The restricted availability of diesel engines in GVW 4 vehicles has pulled the overall diesel engine share down. Cummins leads the industry in share of new diesel registrations with 38.4% of the market.