CleanFUEL USA propane chassis attains certification
The engine and fuel system may now be purchased and used in all 50 states and Canada for up to 33,000 lbs. gross vehicle weight ratio.
CleanFUEL USA, the nation’s first developer of liquid propane fuel injection systems, received Environmental Protection Agency (EPA) and California Air Resources Board (CARB) certification for the S2G chassis from Freightliner Custom Chassis Corp. (FCCC).
The engine and fuel system may now be purchased and used in all 50 states and Canada for up to 33,000 lbs. gross vehicle weight ratio (GVWR).
The chassis, which includes an eight-liter engine built by Powertrain Integration from a General Motors long block and a liquid propane injection (LPI) system manufactured by CleanFUEL USA, will be in full production by early September.
The S2G touts a carbon monoxide rating of 60% below and a nitrogen oxide rating of 20% below EPA set standards for heavy duty vehicles.
In addition to emissions certification, the S2G has undergone years of rigorous and comprehensive reliability testing, such as validation of the complete engine assembly (including the heavy duty accessory drives), engine durability tests, heavy-load testing and multiple rounds of high-altitude, cold and hot weather testing.
The S2G joins other propane autogas vehicles CARB-certified with CleanFUEL USA's LPI system, including the GM 6.0-liter G4500.
More Technology

Turn Transit Data Into Action
Discover how leading agencies are using connected technology to gain real-time visibility across operations, improve service reliability, and reduce disruptions.
Read More →
Biz Briefs: OCTA Taps Clean Energy for Hydrogen Station, Stadler to Supply Via Rail Vehicles, and More
From manufacturers and suppliers to transit agencies and motorcoach operators, these updates offer a snapshot of the projects, partnerships and business moves driving the industry forward.
Read More →
CharterUP Expands Into New Mobility and Autonomous Transportation
Vice President of New Mobility Stephen Joos discusses how CharterUP is leveraging its nationwide transportation network, technology platform, and autonomous vehicle partnerships to expand into workforce mobility, campus shuttles, and transit solutions.
Read More →
METRO Magazine Announces 2026 Innovative Solutions Awards Winners
Projects Recognized for Advancing Mobility Through Technology, Accessibility, Workforce Innovation, and Operational Excellence
Read More →
Cummins Introduces Phased Model Year 2027 Launch Strategy
According to officials, the approach is designed to maintain regulatory compliance, support customer production schedules, and provide additional time to ramp production in a disciplined manner that helps ensure a successful transition for the industry.
Read More →
Biz Briefs: STV teams with Amtrak, Motorcoach Operators Boost Fleet and Land Contracts, and More
From manufacturers and suppliers to transit agencies and motorcoach operators, these updates offer a snapshot of the projects, partnerships and business moves driving the industry forward.
Read More →
DART Taps Nathaniel P. Ford Sr. as Next President/CEO
Since 2012, Ford has served as the CEO of the Jacksonville Transportation Authority
Read More →
AC Transit’s Cecil Blandon on Building the Next Generation of Transit Maintenance Leaders
The agency’s maintenance chief discusses leadership, workforce development, zero-emission technology, and preparing technicians for the future of public transportation.
Read More →
California High-Speed Rail Authority Signs MOU to Advance High Desert Corridor
The agreement deepens collaboration between the California High-Speed Rail Authority and the High Desert Corridor Joint Powers Agency, supporting design integration, cost savings, and faster delivery of a key Southern California rail link.
Read More →
Building the Next Generation of Transit Technology
In this edition of METROspectives, Luminator CEO Magnus Friberg discusses the company's transformation, the growing role of AI and software, and what's next for transit technology.
Read More →