More power options are coming soon to the large school bus space as Cummins prepares to launch a second gasoline engine option for the market and its long-awaited successor to the 6.7-liter diesel engine.
The gasoline or octane engine will be in full production next January, with the new B7.2 diesel engine available January 2027, the company announced earlier this month. The new gasoline engine will be available January 2026.
Both engines are the initial launches of Cummins’ HELM, or Higher Efficiency, Lower emissions and Multiple fuels, platform. The engine lineup is referred to as “fuel agnostic,” the base engine remains the same, but the fuel heads can be swapped for diesel, gasoline and eventually CNG.
Currently, the school bus industry only has one choice in gasoline and propane, that being the ROUSH CleanTech auto-gas system for Blue Bird.
Cummins originally planned on adding a propane offering on its HELM platform but announced last year it would forego that option.
The B7.2 meets the upcoming EPA Greenhouse Gas Emissions Phase 3 rule set to go into effect in 2027. The company said will emit approximately 85 percent less NOx and 50 percent less PM than 2010 model year diesel engines. In an overview provided to School Transportation News, Cummins explained that lower GHG result from the clean-sheet base engine and optimized components.
“One of the most significant changes is the increase in peak cylinder pressure capability, allowing us to extract the energy from the fuel more effectively,” the overview states. “As greenhouse gas emissions are directly proportional to fuel burned, the improvements made to improve GHG emissions also save fuel, reducing the operating costs of the new B7.2.”
The diesel will also be compatible with automatic engine shutdown and stop-start systems that can lower fuel consumption as well as GHG.
On a recent episode of the School Transportation Nation podcast recorded at STN EXPO East, Francisco Lagunas, general manager of the North America bus segment at Cummins, said the B7.2 diesel engine will provide a wider range of torque as the company address the various duty cycles of its customers and the environmental condition they operate in.
“There are big differences north to south, coast to coast. Cummins focuses on reliability and what’s best for the customer,” he added.
This includes ACUMEN that provides access and connectivity to a range of applications for , digital insights.
“Customers can utilize these detailed tools to enhance the driving experience including predictive capabilities and over-the-air features that will reduce visits to the shop, increase uptime and minimize the operations,” Lagunas continued. “It will also take advantage of options like compression brake or extend the oil drain intervals.”
Meanwhile, Lagunas said the new octane engine available next year will provide diesel-like performance for both reliability and durability. He added that fleet operators can expect 10 percent improved fuel economy based on the duty cycle.
Listen to episode 252 of the STN podcast with Francisco Lagunas:
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