Eaton Cummins Endurant
The Eaton and Cummins joint venture box, and the lightest 12-speed in the class by a clear margin. Designed alongside the X15 so the two shift as one calibration rather than negotiating with each other.
Torque rating
1850-2050
pound-feet at the input
Weight
640 lb
the lightest here
Shifting
Actuated
software decides the gear
Maker
Eaton
What it does to fuel
Meaningfully better than a manual, mostly by shifting more consistently than a person and by holding a downsped cruise the driver would instinctively gear out of.
What this type is
The same gearbox with the clutch and the shifting actuated. It is NOT an automatic, it has no torque converter, and it fails and gets repaired like a manual. This is now the default in new linehaul, because software shifts more consistently than a person and consistency is fuel.
Known issues
Too recent for a settled long-term record. Early software calibrations attracted complaints that updates largely addressed.
Verdict
If you are buying a Cummins-powered truck new, this is the box to pair it with, and the weight saving is real payload.