CARB certifies next-generation propane engine in Blue Bird school buses to lowest NOx in market

ROUSH CleanTech is the first original equipment manufacturer to receive California Air Resources Board’s 0.02 grams per brake horsepower-hour certification for 2022 model year vehicles. The optional ultra-low CARB certification is 90% cleaner than current emissions standards for nitrogen oxides.

The new engine certification covers ROUSH CleanTech Gen 5 propane engines for Blue Bird school buses.

Propane is well established as an economical, clean and domestically produced alternative fuel for school buses. “Blue Bird is the leader in clean emissions school buses with over a decade of selling experience, and more than 20,000 clean and cost-reducing propane school buses on the road,” said Matthew Stevenson, president and CEO of Blue Bird Corporation. “Equipping our buses with the lowest nitrogen oxide propane engine is great news for the environment, our customers and our children.”

Nitrogen oxides, known as NOx, are a group of gases known as a primary contributor to acid rain, smog and other air quality issues. According to the Environmental Protection Agency, exposure to NOx can trigger health problems, such as asthma and other respiratory issues, especially in children.

“Since the introduction of our Ford 7.3L V8 propane engine in 2020, our team has worked tirelessly to gain this emissions certification,” said Todd Mouw, president of ROUSH CleanTech. “We remain committed to providing cost-efficient, advanced vehicle solutions for the school bus market that reduce environmental impact.”

This is the second time ROUSH CleanTech has earned the ultra-low NOx certification, previously for its 6.8L V10 propane engine in 2018. The certification is part of a proposed federal emissions regulation that goes into effect in 2027. “We didn’t wait for the regulation to go into law. We’ve already achieved it,” Mouw added.

Blue Bird propane school buses equipped with the ultra-low NOx engines will provide school districts and school bus contractors multiple advantages in seeking funding from the new Infrastructure Investment and Jobs Act’s Clean School Bus Program. The provision provides $2.5 billion for the purchase of low- and zero-emission school buses, including propane which is identified in the legislation as an emerging alternative fuel. Funding is slated to be released beginning in 2022 and continuing through 2026, with project implementation as soon as next year.