Cummins Westport Inc. announced Oct. 4 that it has begun development on the ISB6.7 G, a mid-range 6.7L natural gas engine designed to meet the increasing demand for on-highway vehicles powered by natural gas. 

The ISB6.7 G engine will be based on the Cummins ISB6.7 diesel engine and will use Cummins Westport's proven spark-ignited, stoichiometric cooled exhaust gas recirculation (SEGR) technology. Exhaust aftertreatment will be provided by a maintenance-free three-way catalyst.

The engine will run on compressed natural gas (CNG), however, the natural gas may be stored on the vehicle in liquefied natural gas (LNG) state or as CNG. The ISB6.7 G is expected to be in production by 2015 and will be designed to meet Environmental Protection Agency (EPA) and California Air Resources Board (CARB) regulations in force at the time of launch.

"The addition of the ISB6.7 G will round out our family of high performance natural gas engines," said Jim Arthurs, President of Cummins Westport. "It joins the 8.9-liter ISL G, with over 16,000 engines in service, and the 11.9-litre ISX12 G, which will start production in 2013, to give our customers a broad range of natural gas engines for on-highway applications."