Alternative-fuel technology company Roush CleanTech has developed the first available propane autogas engine certified to California Air Resources Board’s optional low oxides of nitrogen emissions standard for heavy-duty engines with 0.02 grams per brake horsepower-hour (g/bhp-hr). The engine is 90% cleaner than the current U.S. Environmental Protection Agency’s (EPA) most stringent 0.2 g/bhp-hr heavy-duty engine standard.

Nitrogen oxides (NOx) emissions are regulated under federal air quality standards because they are known to be harmful to human health and to the environment, contributing to regional ozone attainment challenges, smog and other air-quality issues. Heavy-duty diesel trucks are the single largest source of NOx emissions, contributing to smog in a majority of the nation’s most populated urban regions. According to the EPA, operating vehicles with ultra-low emission engines can make significant improvements to regional air quality and reduce a wide variety of human health impacts.

This new certification covers all of Roush CleanTech’s 6.8 L V10 3 V propane engines for Class 4-7 vehicles. Installation of the new optional ultra-low NOx engines has begun with some 2018 Ford commercial vehicles and Blue Bird Vision propane school buses. Roush CleanTech, which has deployed more than 18,000 propane autogas vehicles, will manufacture both the low-NOx 0.05 and ultra-low NOx 0.02 g/bhp-hr propane engines.

School, shuttle and transit buses and Class 4-7 medium-duty trucks equipped with ultra-low NOx engines are expected to be very competitive in seeking funding from the Volkswagen Environmental Mitigation Trust settlement.

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