On Thursday, Cummins Westport announced it will develop the ISB6.7 G, a mid-range 6.7 liter natural gas engine. The ISB6.7 G, expected to go into production by 2015, will be designed to meet the certification requirements of EPA and CARB at the time of launch. The ISB6.7 G is based on the Cummins ISB6.7 diesel engine and will use Cummins Westport’s spark-ignited, stoichiometric cooled exhaust gas recirculation (SEGR) technology. A three-way catalyst will provide the exhaust after-treatment. The engine will run on CNG; however, the fuel can be stored on the vehicle as either CNG or LNG. The 6.7 liter engine is designed for medium duty trucks, but other applications might include C-class school buses and vocational vehicles. “The addition of the ISB6.7 G will round out our family of high performance natural gas engines,” said Cummins Westport President Jim Arthurs. “It joins the 8.9-litre ISL G, with over 16,000 engines in services, and the 11.9-litre ISX12 G, which will start production in 2013.”