Orders are being processed and production has started for Cummins Westport’s ISL G Near Zero NOx natural gas engine, the company announced.

The ISL G NZ has received emission certification from the Environmental Protection Agency and Air Resources Board in California to meet the optional 0.02 g/bhp-hr — the first such midrange engine in North America to do so, according to Cummins.

The ISL G NZ has exhaust emissions that are 90% lower than the current EPA and ARB NOx limit and also meet the 2017 EPA greenhouse gas emission requirements.

"The start of production of the ISL G Near Zero natural gas engine offers a game-changing solution for the reduction of urban tailpipe and engine related emissions," said Rob Neitzke, president of Cummins Westport. "The ISL G Near Zero is now at the forefront of cost-effective and dependable emission reduction strategies in transit, medium-duty truck and refuse applications."

The ISL G NZ can operate on compressed, liquid or renewable natural gas. The engine offers low engine ratings from 250-320 horsepower and 660-1,000 lb-ft torque. In addition to NOx emissions reduction, the ISL G NZ will feature closed crankcase ventilation, reducing engine-related GHG methane emissions by 70%.

The ISL G NZ offers improved reliability and durability as well as range and performance with low emissions, through its three-way catalyst (TWC) aftertreatment. TWCs are effective, simple, passive devices, packaged as part of the muffler. Cummins Westport natural gas engines do not require active aftertreatment such as a Diesel Particulate Filter or Selective Catalytic Reduction. 

The ISL G NZ engine is available as a first fit engine with transit, shuttle and school bus, refuse and truck original equipment manufacturers or as an engine replacement (repower) for existing ISL G vehicles.