Natural gas-powered Class 8 truck sales have fallen off almost 30% compared to last year’s numbers.

That’s the word from a ACT Research in a new quarterly report that details market activity for natural gas-powered trucks through August of this year. The report notes that natural gas-powered Class 8 truck sales rose 13% in 2017, but have slid by 28% so far this year.

“On a nominal basis, natural gas retail sales are down about 600 units for the first eight months of 2018 on a year-over-year basis,” said Ken Vieth, senior partner and GM of ACT Research. “Based on news released in the popular press, natural gas vehicle purchases continued to be dominated by refuse fleets, as well as by transit and school bus operators.”

Vieth added, “With the narrowed fuel price spread between diesel and natural gas, it really isn’t surprising that sales of natural gas units softened. That said, it is important to remember that the conversion of a fleet from diesel to natural gas doesn’t rest entirely on the savings of fuel. Natural gas offers more consistent fuel pricing and is one way fleets can meet more stringent environmental requirements, particularly where RNG is available.

“Transportation power is no longer a one-size-fits-all proposition," he continued. "All viable commercial vehicle power alternatives, from diesel and NG to EV of all kinds, must now be considered to accurately measure potential cost savings, while meeting future emissions.”

More details on ACT Research’s latest report on natural gas powered trucks can be found here.