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Three Things to Know About PSI’s Certification

Three Things to Know About PSI’s Certification

Recently, PSI received California Air Resources Board (CARB) certification for its model year 2019 8.8L propane and gasoline engines. This means that IC Bus remains a key player and competitor in alternative fuel school buses with both Environmental Protection Agency and CARB certification. Here are the facts:

  1. PSI’s current certification is to the federal standard nitrogen oxides (NOx) level of 0.20 g/bhp-hr.

 – By comparison, ROUSH CleanTech’s propane engine is certified for both low NOx at 0.05 g/bhp-hr and ultra-low NOx at 0.02 g/bhp-hr. That’s 75 to 90 percent cleaner than the federal standard PSI has obtained.

 – To get low-NOx certification, the engine must test statistically below the threshold. PSI’s result was 0.13g. Compare that to ours at 0.01g!

  1. For model year 2019, CARB required PSI to do evaporative testing, which, for the first time, included the fuel tank.

 – PSI’s certification includes 47- and 68-gallon propane tanks only.

 – Our certification includes all fuel tank offerings: 47, 67 and 93 gallons.

  1. PSI’s engines are certified on the IC Bus CE model, but also on the Freightliner B2 and S2G chassis. This may be a precursor for what we’ll see on the Thomas Built Buses C2 model.

It’s your success with propane that is keeping the competition in the game whether they want to be or not. We are the industry leader with complete and cutting-edge offerings.

If you have any questions or would like more information to combat the competition in your area, reach me at