Cummins Debuts First Gasoline Engine

The new B6.7 Octane is based on the brand’s well-known B6.7 inline-six diesel platform and is designed for medium-duty commercial trucks, offering a diesel-like alternative without emissions system complexities.

The engine produces up to 300 horsepower and 660 pound-feet of torque, with lower-output versions making around 200 hp and 600 lb-ft. While torque delivery isn’t quite as low in the rev range as its diesel counterpart, peak torque still arrives around 1,600 to 1,800 rpm. Cummins says the B6.7 Octane runs on regular 87-octane gasoline and offers 10% better fuel efficiency than comparable gas engines. It is already CARB and EPA 2027 compliant, though evolving emissions regulations may shift those standards.

The B6.7 Octane has undergone 2 million miles of testing and is the first B-Series engine built on Cummins’ HELM platform—short for Higher Efficiency, Lower Emissions, and Multiple Fuels. Launched in 2024, HELM is designed to reduce emissions, increase fuel efficiency, and allow modifications for alternative fuels. The new engine is CARB and EPA 2027 compliant and will first appear in Kenworth Class 5 to 7 trucks, including the T180 to T480 models.

“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, and towing applications. 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.”

Cummins has yet to confirm whether the B6.7 Octane will expand to other applications—regardless, its a significant step from a company best known for diesel power.

Become an AutoGuide insider. Get the latest from the automotive world first by subscribing to our newsletter here.