Roush CleanTech Offers Propane Autogas Medium-Duty Engine

First propane autogas engine for Class 4-7 vehicles is now certified by the EPA and CARB, at 75% cleaner than current diesel emissions standard

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Roush CleanTech developed the first propane autogas engine available in Class 4-7 vehicles and Blue Bird Type C buses certified to the optional low nitrogen oxide (NOx) level .05 g/bhp-hr. These new propane engines, certified by the Environmental Protection Agency and California Air Resources Board, are 75% cleaner than the current emissions standard.

“Roush CleanTech’s low NOx engine is a great step forward for the propane industry,” said Tucker Perkins, president of the Propane Education & Research Council. “Propane autogas is well established as an economical, clean-burning and domestically produced alternative fuel ideal for fleets. Now propane gets the biggest return on NOx reductions, too.”

Nitrogen oxides are a group of gases known as a primary contributor to acid rain, smog and other air quality issues. The EPA states that exposure to NOx can trigger health problems such as asthma and other respiratory issues. CARB has encouraged heavy-duty engine manufacturers to reduce levels below the current mandatory EPA standard of .2 grams per brake horsepower per hour (known as g/bhp-hr).

The certification covers Roush CleanTech 6.8L V10 3V propane engines for school bus and commercial truck engines with no additional upfront cost. Roush CleanTech has begun installing the new low NOx engines in its Ford commercial vehicles and Blue Bird Vision propane school buses with 2017MY engines.

“Developing the lowest NOx propane engine sends a message that this fuel is comparable to other alternative fuels from a standpoint of emissions,” said Todd Mouw, vice president of sales and marketing for Roush CleanTech. “With our nation’s ample supply of propane and the fuel’s favorable total cost of ownership, our propane autogas engine is the perfect mix of environmental and economic sustainability.”

Roush CleanTech is a division of Roush Enterprises based in Livonia, Mich., that designs, engineers, manufactures and installs propane autogas fuel systems for medium-duty Ford commercial vehicles and Type A and Type C Blue Bird school buses. Roush CleanTech also installs compressed natural gas fuel systems for Type C Blue Bird school buses. Learn more at

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