The programmatic goal is to enable natural gas engines that can cost-effectively achieve diesel-like efficiency while meeting current and future emissions standards. A complete engine development project is outside the scope of this effort, but engine subsystem research must have a plausible pathway to higher engine efficiency.

Emission control technology projects addressing criteria pollutants and GHGs are desired, with consideration that future standards are likely to influence NGV technology adoption. Potential technologies include (but are not limited to) combustion strategies, engine subsystems, emission control systems, fuel systems, and controls.

As the world’s leading natural gas producer, the United States could benefit from using low-cost natural gas as an alternative to other energy sources for transporting goods. Opportunities exist to improve performance, reliability, durability, cost effectiveness, and efficiency of natural gas vehicles through research and development.

A public workshop on natural gas vehicles was held at the National Renewable Energy Laboratory on 25 July 2017 to identify early-stage research needs for natural gas engines, including topics in engine efficiency, emissions control and fuel and fuel systems.

Broadly, key observations from the workshop included:

• Industry feedback showed interest in low TRL level aspects of natural gas efficiency, as well as lubricant effects and advanced modeling; industry would like to see DOE continue building on expertise with liquid fuel engine systems.

• Both criteria air pollutants and GHG control are of interest for NG vehicles, research needs exist for addressing the unique NG challenges of methane conversion for all combustion strategies

• There are several low and medium TRL research topics related to NG fuels and fuel systems which can increase of MD/HD NG vehicles. These may not be directly related to FY17 goals of engine efficiency improvements but represent a critical piece of overall NGV efficiency.