COLUMBUS, Ind. — The adoption of natural gas as an alternative to diesel fuel in the heavy-duty truck segment will continue to grow, but at a slower pace than first expected.

That, according to the latest report from ACT Research, NG Reality Check: Moving from Infancy to Adolescence.

The first such report issued by ACT projected faster growth for natural gas trucks, however softening diesel prices have had an impact, the industry forecaster admits.

“The previous long-term penetration overstatement does not mean natural has not grown. It has and will continue to grow, but at a slower rate the next few years,” said Ken Vieth, ACT Research’s senior partner and general manager. “NG Class 8 truck/transit bus penetration was 3% in 2013 and should reach 4% in 2014, or about 11,000 units.”

ACT projects natural gas vehicles will account for 23% of Class 8 truck and bus vehicles sold by 2025. If total Class 8 demand totals 200,000 units that year, then 46,000 of them will be fuelled by natural gas.

“That’s a large quantity that will be shared by those with an understanding of tomorrow’s truck transportation needs and plans to get there,” Vieth said. “Depending upon the emissions and greenhouse gas needs of the nation and the regulations put in place in coming years to achieve those needs, NG penetration could even be higher since NG is equally available and is a cleaner, cheaper (CPM) fuel than diesel.”

The full report is available by e-mailing trucks@actresearch.net.