Blue Bird Offering Engine Certified to Low NOx for Propane School Buses
The engine, developed in partnership with Roush CleanTech, is certified at 0.02 g/bhp-hr of nitrogen oxide.

Blue Bird is now offering an ultra-low nitrogen oxide certified engine in its propane school buses. File photo of Blue Bird Vision propane buses

Blue Bird is now offering an ultra-low nitrogen oxide certified engine in its propane school buses. File photo of Blue Bird Vision propane buses
FORT VALLEY, Ga. — Blue Bird is now offering an ultra-low nitrogen oxide (NOx) certified engine in its propane school buses.
Certified by the U.S. Environmental Protection Agency (EPA) and California Air Resources Board (CARB) at 0.02 g/bhp-hr of NOx, the engine is available as an option for Blue Bird’s Vision Propane buses. Developed in partnership with Roush CleanTech, the engine is 90% cleaner than the current 2010 emissions standard and 99% cleaner than pre-2007 standards, according to Blue Bird.
“A school district can operate 100 buses with the 0.02 NOx engines and emit less NOx emissions than one diesel bus manufactured before 2007,” said Todd Mouw, president of Roush CleanTech. “Our nation has an abundant supply of propane; combine that with the economic and environmental benefits, and it’s no wonder that more than 850 school districts have already chosen propane buses.”
Last year, Blue Bird made a 0.05 g/bhp-hr NOx Ford 6.8L engine available in its Vision Propane buses, which at the time operated with the lowest NOx levels of any engine in Class 4 to 7 vehicles on the market, according to the school bus manufacturer. CARB has further encouraged engine manufacturers to reduce levels below the current mandatory EPA standard of 0.2 grams per brake horsepower hour (known as g/bhp-hr).
“Our overarching goal is to continually build a better bus that provides a clean and safe environment for our students and communities,” said Mark Terry, chief commercial officer of Blue Bird.
Terry added that Blue Bird is continuing to make investments to ensure the bus exceeds customers’ expectations with its low NOx emissions and ownership costs.
The new engine could allow districts to take advantage of many opportunities, according to Blue Bird, including:
• Additional grant incentives, as well as higher levels of funding, including from the Volkswagen (VW) settlement.
• Federal and local rebates and incentives for alternative fuels, saving some districts up to $3,500 per bus annually on fuel and maintenance costs.
• Further reducing negative environmental impacts and improving air quality for children who suffer from asthma-related symptoms and other breathing issues.
Over the past year, NOx has received attention because of the VW settlement. The automaker’s $2.9 billion Environmental Mitigation Trust will fund actions that reduce excess NOx emissions. As a result, many states are including alternative-fuel school buses in their funding models.
“Many school districts will have access to funding to replace aging diesel models with clean-burning propane buses,” Mouw said.
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