ROUSH CleanTech has received California Air Resources Board certification for 2023 model year propane engines at 0.02 grams per brake horsepower-hour. Previously available as an added-cost option, the ultra-low nitrogen oxide (NOx) emissions package is now standard on every propane engine sold by ROUSH CleanTech.
The engines emit 90% less NOx emissions than allowed under 2023 regulations, and are 60% cleaner than California’s 2024 low-NOx standard, without compromising performance or efficiency.