The ISB6.7 G natural gas engine is based on the Cummins ISB6.7 diesel engine platform. The ISB6.7 G is fueled by compressed natural gas (CNG), liquefied natural gas (LNG) or renewable natural gas (RNG), utilizing Cummins Westport’s proprietary spark-ignited, stoichiometric combustion with cooled Exhaust Gas Recirculation (SEGR) technology. Currently in field trials, the ISB6.7 G will be in full production by mid-2016.

An important feature of the ISB6.7 G is Three-Way Catalyst (TWC) aftertreatment, which is packaged as a muffler, and is maintenance-free. No Diesel Particulate Filter (DPF) or Selective Catalytic Reduction (SCR) aftertreatment will be required.

Preliminary specifications include a range of ratings up to 260 hp (194 kW) and 660 lb-ft (895 N·m) torque, and automatic transmission capability, to meet customer and original equipment manufacturer (OEM) requirements. The ISB6.7 G will be manufactured at the Cummins Rocky Mount Engine Plant in Whitakers, N.C.

The ISB6.7 G will be certified at launch to meet the U.S. Environmental Protection Agency (EPA) and California Air Resources Board (ARB) emissions standards of 0.20 g/bhp-hr nitrogen oxides (NO_x) and 0.01 g/bhp-hr particulate matter (PM), and 2017 U.S. greenhouse gas (GHG) and fuel-economy regulations.