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Cummins Westport Expands Market for Midrange Natural Gas Engine


Cummins Westport announced the ISB6.7 G, a 6.7-liter midrange, factory built natural gas engine is now available as a production engine for shuttle bus, medium duty truck, and vocational applications in North America. The engine has been available for school bus applications since May 2016 from Thomas Built Buses. Now, the applications available for the ISB6.7 G engine expand to midrange trucks, vocational trucks and mid-size buses, more than doubling the addressable market.

The ISB6.7 G is based on the Cummins ISB6.7 diesel engine platform, and operates exclusively on natural gas, including CNG, LNG, or renewable natural gas (RNG). The ISB6.7 G is the second engine from CWI to receive emission certification from the U.S. Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) for meeting the Optional Low NOx Emissions standards.

“We are pleased to announce the ISB6.7 G is now in full production and available for all of our customers and OEM partners,” said Rob Neitzke, President of CWI.  “An engine of this size is a natural addition to CWI’s portfolio of natural gas engines. The ISB6.7 G offers the midrange customer an ability to take advantage of the most cost effective overall solution with the benefit of a low emission natural gas engine that has proven performance, reliability, and durability.

NOx emissions of the ISB6.7 G are 50 percent lower than the current EPA and CARB NOx limit. Additionally, CO2 emissions meet the 2017 EPA greenhouse gas emission requirements, and all CWI natural gas engines are lower than the 2010 EPA standard for particulate matter.

The ISB6.7 G uses CWI’s proprietary spark-ignited, stoichiometric combustion with cooled exhaust gas recirculation (SEGR) technology.  It features electronic control with programmable features, a closed crankcase ventilation system, and maintenance-free three-way catalyst after-treatment.  No diesel particulate filter or selective catalytic reduction after-treatment is required.

The ISB6.7 G will be manufactured in the Cummins engine plant. Partial funding in support of the ISB6.7 G engine development has been received from the California Energy Commission (CEC) through its Public Interest Energy Research (PIER) Program in conjunction with the Gas Technology Institute.