New Ultra-Low NOx Propane Engine Available for Some IC School Buses

IC Bus and engines and power systems manufacturer Power Solutions International Inc. (PSI) have released a new 8.8-liter ultra-low nitrogen oxide (NOx) emissions propane engine for the school bus manufacturer’s CE Series school bus.

The engine, which was produced and purpose-built for the school bus industry as a collaboration between IC Bus and PSI, recently received certification from the U.S. Environmental Protection Agency (EPA) and California Air Resources Board (CARB) and is now available for order, according to news releases from both manufacturers.

With these approvals, customers looking to make the switch from diesel to propane are eligible for additional grant funding for their school bus purchases. Customers will still be able to purchase a bus with the conventional 8.8 propane engine in addition to this new offering, according to IC Bus.

“Propane is a growing segment for us, and we are proud to now offer an even cleaner solution to our customers,” said Trish Reed, vice president and general manager of IC Bus. “This new engine promises to deliver on our customer’s high standards for performance, durability, safety and environmental impact.”

The PSI high-performance V8 propane engine is designed to handle the rigors of on-road duty, delivering a clean-technology solution without sacrificing power or performance. The engine’s reportedly superior performance is driven by an engine control unit that integrates and coordinates all critical functions, including governor, variable ignition timing, air/fuel ratio control, knock suppression, and engine protection.

The engine offers 270 horsepower with 565 pound-foot of torque, comparable to PSI’s existing propane engines. It is certified to a NOx emission standard of 0.02 grams per brake horsepower (g/bhp-hr), making it one of the cleanest propane engines available on the market, according to the manufacturers. The engine has been certified beyond the EPA’s strictest emission standards and exceeds CARB’s optional low NOx standard for heavy-duty engines.

PSI will continue to offer its conventional 8.8-liter propane engine as well as the new ultra-low NOx version.

Over the past few years, IC Bus and PSI have collaborated to bring propane- and gasoline-powered alternatives to the school bus industry in an effort to reduce NOx emissions, which are known to be harmful to humans and the environment and contribute to ozone, smog, and other air quality issues.

“PSI is proud to support the growth of our customer, IC Bus, which first introduced the 8.8-liter propane engine in 2015,” said PSI CEO John Miller. “We continue to make advancements to our 8.8-liter engine, which is clean burning and unmatched in power and performance in the transportation industry.”

In addition, the IC Bus CE Series, which is powered by PSI’s propane engine, comes with a five-year unlimited miles warranty for the PSI engine and fuel system, and a seven-year unlimited miles warranty for the Allison Transmission. All warranty work on the PSI engine and Allison transmission can be serviced at the customer’s local IC Bus dealer.

Production is anticipated early next year, according to PSI.