Research Projects

Project at a Glance

Project Status: complete

Title: Development, demonstration & commercialization of a 0.20 G/BHP-HR NOx natural gas engine

Principal Investigator / Author(s): Cummins Westport, Inc.

Contract Number: ICAT 06-08

Research Program Area: Emissions Monitoring & Control

Topic Areas: ICAT Grants / Technology


Cummins Westport commenced commercial production of the 8.9 liter ISL G natural gas engine in June, 2007, with ARB certification to the 2010 on-highway emission standard. The ISL G engine uses stoichiometric, cooled EGR, spark ignition (SESI) combustion technology in conjunction with a three way exhaust catalyst, a passive device which is highly effective at passive NOx conversion. The ISL G target markets at launch were transit buses and refuse collection trucks. Following ISL G launch, CWI and ARB executed ICAT Grant Agreement 06-08 to further develop & demonstrate the ISL G engine in medium duty truck applications, leading to factory availability from a major medium duty truck OEM. The scope of work included developing additional performance rating & hardware options to enable the ISL G engine to be installed in medium duty trucks, as well as enabling installation in a wide range of other commercial vehicle applications, including yard tractors, street sweepers, school buses, and shuttle buses. The project deliverable would be a version of the ISL G that is commercially available for use in medium duty trucks and the specialty vehicle applications identified above.

Cummins Westport has developed two additional ratings for the ISL G, and a new “low-mount” turbocharger option to enable ISL G integration in Freightliner’s popular M2 truck model. These new options became commercially available in early 2009, and are in widespread commercial use by fleet customers. Pacific Gas & Electric has operated an ISL G-powered truck in its fleet operations for approximately 12 months. Freightliner has commercialized multiple ISL Gpowered versions of its M2 truck. The OEM availability of ISL G-powered vehicles has expanded significantly during this ICAT project, and includes major vehicle manufacturers in each of the target market segments identified above.


For questions regarding research reports, contact: Heather Choi at (916) 322-3893

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