Roush CleanTech developed a propane autogas engine for class 4-7 vehicles and Blue Bird Type C buses certified to the optional low nitrogen oxide (NOx) level of .05 grams per brake horsepower per hour (g/bhp-hr).
The engine received both Environmental Protection Agency (EPA) and California Air Resources Board (CARB) certification. According to Roush CleanTech, nitrogen oxides are gases known to be primary contributors to acid rain, smog and other air quality issues. EPA notes that exposure to NOx can trigger health problems such as asthma, and CARB has encouraged heavy-duty engine manufacturers to reduce levels below the current mandatory EPA standard of .2 g/bhp-hr.
The certification covers Roush CleanTech 6.8-liter V10 3V propane engines for school bus and commercial truck engines. Roush CleanTech began installing the new, low NOx engines in its Ford commercial vehicles and Blue Bird Vision propane school buses, Roush CleanTech adds.
In addition, NOx awareness increased this past year due to the Volkswagen emissions compliance issue. The Volkswagen Environmental Mitigation Trust was created to fund actions with cleaner technology that reduce excess emissions of NOx, Roush CleanTech says.
“Our .05 NOx engine certification will help our school bus and public transit customers target funds from the upcoming [Volkswagen] Environmental Mitigation Trust program,” says Todd Mouw, vice president of sales and marketing at Roush CleanTech. “This is especially beneficial for school districts looking for extra funds to replace aging diesel models.”