A Cummins Westport ISL G engine. Photo: Cummins Westport

A Cummins Westport ISL G engine. Photo: Cummins Westport

Cummins Westport’s ISL G Near Zero NOx natural gas engine has received Near Zero NOx emission certifications from the U.S. Environmental Protection Agency and California Air Resources Board, the company announced.

The ISL G is the first mid-range engine to meet the 0.02 g/bhp-hr optional Near Zero NOx Emissions standards for medium-duty truck, urban bus, school bus, and refuse applications, according to Cummins Westport Inc. The ISL G NZ meets CARB certification eight years in advance of the 2023 California Near Zero NOx schedule.

"In Southern California, clean, zero- and near-zero emission vehicle technologies are critical to meeting clean air standards," said Barry Wallerstein, executive officer for the South Coast Air Quality Management District. "Cummins Westport's new engine provides an important tool toward reaching that goal."

In addition to a 90% reduction in NOx emissions, the ISL G NZ will feature closed crankcase ventilation, which reduces engine-related methane emissions by 70%, according to CWI. The engine also makes use of a CWI's Three-Way Catalyst passive aftertreatment and does not require active aftertreatments like diesel particulate filters or selective catalytic reduction.

Performance will match current ISL G engines with ratings that range from 250 to 320 horsepower and 660 to 1,000 lb.-ft. of torque. The base warranty, extended coverage options, and maintenance procedures and intervals will also match the current ISL G engine.

The ISL G NZ is expected to enter production in April 2016 and will be made available as a first fit engine with transit and refuse OEMs and as an engine replacement for existing ISL G vehicles. CWI is also currently assessing Near Zero product plans for its ISB6.7 G and ISX12 G engines.