A near-zero emission engine technology that brings
clean solutions for medium heavy-duty trucks today.

Through an agreement with South Coast Air Quality Management District, Cummins Westport, Inc. was awarded Energy Commission Natural Gas R&D and ARFVTP funds to help support the development and on-road demonstration of a new near-zero NOx natural gas engine to be used in the medium heavy-duty truck market. In October 2015, this engine become the first midrange engine in North America to receive emission certifications from both U.S. Environmental Protection Agency (EPA) and the California Air Resources Board (ARB) that meet the 0.02 g/bhp-hr optional Near Zero NOx Emissions standards for medium heavy-duty truck, urban bus, school bus and refuse applications.

The engine has already exceeded the 2016 DOT/EPA standards for Greenhouse Gas Emissions and is on track to exceed proposed future standards as well. While the engine has been heavily modified to reduce its GHG emissions, the performance is comparable to that of its diesel powered counterpart. Cummins Westport created their low NOx engine to be used in the transit, refuse, vocational, and bus industries as well as any other medium heavy-duty truck application. This new engine is a critical technological advancement, offering an immediate commercially-available technology to help achieve the state’s sustainable freight, clean air, and climate goals.

See more information about Cummins-Westport Low-NOx Engine .

  Refuse truck powered by the Cummins Low NOx engine.

Photos courtesy of California Energy Commission



  • Certified to CARB Optional Low NOx 0.02 Standard.

  • Exhaust emissions expected to be 90% lower than the current EPA NOx limit of 0.2 g/bhp-hr.

  • Engine expected to meet the 2017 EPA greenhouse gas emission requirements.

Type of Project

Low NOx CNG Engine

ARFVTP Award Amount


R&D Natural Gas Funding


Match Funding



Operational, with field testing underway.


The Cummins-Westport Low-NOx Engine project is located in  the South Coast Air Basin in California


Caterpillar Inc.

Medium- and Heavy-Duty Advanced Vehicle Demonstration

CleanWorld Partners, LLC

Biofuel Production Plant

Community Fuels

Biofuels: Biodiesel

Electric Vehicle Charger Support

Electric Vehicle Charging Infrastructure

Electric Vehicles International

Electric Vehicle Manufacturing

Springboard Biodiesel, LLC

Biofuels: Biodiesel

Valley Garbage and Rubbish Company, Inc.

Natural Gas Infrastructure

Driving to Cleaner Transportation

Project Photo Tour