CleanFUEL USA and Freightliner Custom Chassis Corp. have partnered to build and certify a multi-purpose 8-liter General Motors (GM) propane engine.

The first versions will be used for a Thomas Built Buses Type C school bus and a Freightliner straight truck chassis.

SBF first reported on the development of a Thomas Built propane bus last month. It is targeted to be launched in 2012.

The medium-duty engine will feature CleanFUEL’s new 8-liter liquid propane injection (LPI) system, which the company says gives fleet managers a high-performance alternative to reduce operating costs and greenhouse gas.

Freightliner will certify CleanFUEL’s LPI system to run on the Thomas Built Type C school bus and a Freightliner straight truck chassis. Conversion kits also will be available to switch medium-duty gasoline vehicles to run on propane.

“We’ve seen an industry-wide shift to becoming more environmentally conscious, and our customers are requesting more options for green-fleet vehicles,” said Jonathan Randall, director of sales and marketing for Freightliner Custom Chassis Corp. “Working with CleanFUEL to address the demand for green vehicles was a natural fit.”

The Propane Education and Research Council approved a $3.9-million grant to support the project’s development. CleanFUEL, Freightliner Custom Chassis Corp., GM and Powertrain Integration will co-fund the project.