Cummins Unveils New B7.2 Diesel Engine

March 6, 2025

Matt Wolfe

The new B7.2 diesel is the latest engine to be developed using Cummins’ HELM platform. (Cummins)

Cummins has unveiled the latest iteration of its renowned B series engine at its press conference during NTEA’s Work Truck Week 2025 in Indianapolis. The new B7.2 diesel is the latest engine to be developed using Cummins’ HELM platform and will serve a variety of medium-duty applications.

The B7.2 will be capable of automatic shutdown and stop-start operation and, for the first time, offer a compression release engine brake. (SAE/Matt Wolfe)

“Our B engine is a legend known around the world. We are proud to unveil the newest version, the B7.2 diesel engine, right here in our backyard,” said Brett Merritt, vice president and president – Engine Business. “The B7.2 brings the latest technology and advancements to one of our most proven platforms. Combined with the rest of our medium-duty lineup, our customers will have the right engine choices to fit their business needs.”

The new diesel engine will serve a variety of medium-duty applications. (Cummins)

“By many measures, the B engine has been one of the most successful franchises that we have in the Cummins history,” said José Samperio, vice president and general manager for Cummins On-Highway Business in North America. “This engine is the next evolution of the commitment we have for making our products more efficient, cleaner and more durable.”

The new B engine has increased in displacement from 6.7 to 7.2 liters – with a 107-mm (4.213-in) bore and 133-mm (5.236-in) stroke – which allows for a wider range of torque offerings, creating flexibility for different applications and duty cycles.

The B7.2 will reportedly improve unrestricted top-end power ratings, providing a range of 240-340 hp (179-254 kW) and 650-1,000 lb-ft (881-1,356 Nm) of torque with a maximum governed speed of 2,400 rpm. It is an inline-six architecture with a DOHC cylinder head and four valves per cylinder with high-pressure direct common rail injection. At launch the B7.2 will not feature any form of cam phasing, but this technology can reportedly be added later if necessary. Total dry weight of the engine is 1,359 lb (616 kg) with a system weight of 1,607 lb (729 kg).

The B7.2 will also be capable of automatic shutdown and stop-start operation and, for the first time, offer a compression release engine brake. It is equipped with a Holset turbo and a “next generation” aftertreatment and EGR (exhaust gas recirculation) system with an integrated cooler that meets current EPA 2027 requirements. It also features the same belt-driven 48-volt alternator as other HELM engines and an improved oil drain interval over the outgoing 6.7-L.

Series production of the B7.2 is expected to begin in North America in 2027. (Cummins)

“From a performance point of view, the additional torque from the increased displacement is going to ensure we don’t have a gap between the B and the L engine,” Gary Beshears, product strategy manager at Cummins, told SAE Media at Work Truck Week. “Our goal was going to give customers who may be on the bubble between the B or the L engine being the right choice. This new engine is going to allow us to raise the gross vehicle weight of the B engine across the board. Not orders of magnitude, but enough to make a difference.”

Beshears also discussed further details on the B7.2 and some of the ongoing testing that Cummins is performing before commercial launch. “There are a few things that have been carried over from the larger HELM architectures down to this size, like the 48-volt alternator and the 5-kW heaters on the two different cans of the aftertreatment,” he shared. “We are working to determine if we need an intake heater. There’s ongoing testing that looks promising enough to potentially not need one. Of course, we will still have optional pan and block heaters for cold climates that need them.”

The B7.2 engine is slated to be manufactured at Cummins’ Rocky Mount Engine Plant in North Carolina. Cummins states that series production of the B7.2 will begin in North America in 2027.