Street Smarts: Cummins launches three new medium-duty engines

Even a single new commercial vehicle engine launch is a pretty big deal. They don’t happen every day after all.

So, when Cummins announced three new medium-duty engines, it was – needless to say – an incredibly big deal. The launches all came in early March at the NTEA Work Truck Week 2025. And the new engines reflect the current state of flux in the commercial vehicle market.

Cummins has been clear that it will develop any and all viable powertrain solutions and technologies. Its goal is to give fleets and operators as many fuel and propulsion options as possible in order to let the market decide which technologies will win out over time.

Accordingly, all three new engines were designed with Cummins’ HELM architecture. HELM is an acronym for Higher Efficiency, Lower emissions and Multiple fuels.

A Clean Gasoline Engine

Proving the above point, the OE introduced its new B6.7 Octane gasoline-fueled engine at the show. It will be EPA 2027 certified and meet strict California Air Resources Board (CARB) low NOx regulations.

The new B6.7 Octane gasoline engine highlights Cummins’ commitment to provide flexible fuel options for its customers. (Photo: Cummins)

The new engine will be available for order later this year in Kenworth’s line of Class 5-7 conventional trucks and paired with the Paccar TX-8 automated transmission.

Cummins said the new gasoline engine provides diesel-like performance. Power ratings range from 200 to 300 hp. The engine produces up to 660 lb.-ft. of torque.

The B6.7 Octane is 10% more fuel efficient than other gasoline engines in its category, Cummins said. It has an extended oil drain interval of up to 15,000 miles.

“The engine was validated against the same standards as Cummins’ diesel B6.7 engine,” said Kevin Haygood, Kenworth assistant general manager for sales and marketing. “With environmental regulations changing, it spurred us to offer another engine option to our customers. The new Cummins B6.7 Octane engine will meet stringent emission regulations, so we expect it to be a popular option in California and other states that have adopted CARB’s standards.

“It can be a great fit for many of our customers’ applications, especially in P&D (pickup and delivery) and towing applications,” he continued. “We also see it being popular for the lease and rental markets, as well as for landscapers, where those behind the wheel are used to driving gas-powered vehicles.”

New Diesel Aimed at Broader Applications

Of course, Cummins isn’t abandoning diesel for gasoline. It also announced a new B7.2 diesel engine at NTEA Work Truck Week in Indianapolis. It is designed to serve in a variety of medium-duty and vocational applications, including bus, P&D, utility, refuse, towing and more.

The 7.2 L B7.2 diesel engine for medium-duty and vocational applications will provide 240 to 340 hp and 650 to 1,000 lb.-ft of torque. (Photo: Cummins)

“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,” Brett Merritt, vice president and president, Cummins Engine Business, said at the time of its unveiling. “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, with the power and dependability they have come to expect from Cummins.”

The new engine features a slightly higher displacement than its predecessor, increasing to 7.2 L. It is designed to be a global platform that allows customers to ensure their vehicles are ready for what’s to come without sacrificing performance or durability.

“Our customers have used the B-Series engine for more than 40 years and rely on it every day to meet their needs,” said Jose Samperio, vice president, Cummins, North America On-Highway. “It was important that we offer the reliability and performance that they have come to expect, while also creating an engine that is built to last for the future.”

The B7.2 will improve unrestricted top-end performance ratings compared to its predecessor, Cummins stated. It will provide 240 to 340 hp and 650 to 1,000 lb.-ft of torque.

Designed for Heavy-Duty Performance

Last but not least was the new Cummins X10 HELM engine. According to Samperio, the new X10 is designed to deliver heavy-duty performance in a midsize package.

“We’re incredibly proud to introduce the X10,” Samperio said. “Designed to replace the L9 and X12 platforms, the X10 brings robust capabilities, exceptional durability and unmatched versatility to customers looking for heavy-duty performance in a more compact, efficient package. We’re confident the X10 will offer our customers the right engine to help them meet their operational goals.”

Jack Roberts is a Tuscaloosa, Ala.-based independent journalist and licensed commercial driver with more than 20 years’ experience covering the North American and global trucking industries.

The X10 is designed with two ratings sets to offer customers flexibility when powering their vehicles. For heavy-duty applications, the X10 provides up to 450 hp and 1,650 lb.-ft. of torque, providing customers with an optimal balance of power and reliability. For applications requiring a medium-duty package, the engine delivers ratings up to 380 hp and 1,250 lb.-ft. of torque, enabling strong performance across a variety of demanding applications.

Samperio said the X10 provides a class-leading power-to-weight ratio. This gives customers a combination of exceptional performance and efficiency, designed to enhance productivity without weighing down vehicles, he added.

For those needing flexibility in how power is used, the X10 provides increased power take-off (PTO) capability of 590 lb.-ft. continuous and up to 664 lb.-ft. intermittent, providing vocational truck customers with enhanced power and versatility. This increased PTO output allows for more efficient operation of auxiliary equipment.

Editor’s note: this story first appeared in the April 2025 issue of Power Progress.