Cummins Westport Inc announced that an ISL G in-use emissions test performed on an urban transit bus recorded emissions significantly lower than the 2010 EPA and California Air Resources Board (CARB) heavy-duty emission regulations. The Cummins Westport (CWI) 8.9-liter ISL G natural gas engine features new combustion technology (Stoichiometric cooled EGR).
To test the ISL G, Cummins Westport with the support of Sacramento Regional Transit District commissioned Sensors Inc to perform an in-use tailpipe emissions test in accordance with EPA's Heavy Duty In-Use Testing guidelines.
The test was conducted on a 2008 40 ft Orion VII Low Floor natural gas bus powered by an ISL G 280, driven by a Sacramento Regional Transit bus driver on city and highway routes. The US EPA in-use testing procedures were designed such that the heavy-duty engine emissions are controlled over the full range of speed and load combinations commonly experienced in vehicle applications.
Sensors Inc concluded that emissions were significantly lower than 2010 EPA heavy-duty in-use emission requirements.