You actually have two Cummins engine options available for this particular model, the X12 and X15. These are both diesel ...

The first of several Kenworth T680s equipped with the Cummins X15N CNG engine was delivered to UPS in late February. The next-generation X15 diesel is part of Cummins' new HELM fuel-agnostic ...

How is the newest version of the Cummins X15 diesel engine meeting EPA's 2027 Phase 3 greenhouse gas emissions regulations? The Cummins X15N natural gas truck engine produces between 400-500 hp ...