While some enthusiasts appreciate the updates, this particular change has sparked debate and drawn some criticism.
At the start of 2025, Cummins unveiled its updated lineup of heavy-duty (HD) trucks under the Ram 2500 and Ram 3500 badges. Like the smaller Ram 1500, the larger HD models received a comprehensive refresh, featuring updated exterior styling, revamped interiors, new technology, and significant powertrain upgrades.
A standout change in the 2025 Ram HD lineup is the evolution of the 6.7L Cummins turbo diesel engine, a workhorse that has powered Ram trucks since 2007. For 2025, the engine undergoes several key enhancements, including a slight bump in horsepower — from 420 hp to 430 hp — while maintaining 1,075 lb-ft of torque. Additionally, it is now paired with an all-new TorqueFlite HD eight-speed automatic transmission, replacing the previous six-speed unit.
A major highlight for Ram 2500 buyers is the long-awaited arrival of the high-output (HO) version of the 6.7L Cummins. Previously exclusive to the Ram 3500, the HO variant now brings 430 hp and 1,075 lb-ft of torque to the 2500 series. This is a significant step up from the outgoing 2024 Ram 2500, which featured a lower-output version of the same engine with 370 hp and 850 lb-ft of torque, forcing buyers to upgrade to the Ram 3500 for maximum performance.
Aside from these noticeable performance gains, the updated Cummins 6.7L features several notable mechanical improvements, including a more reliable Bosch CP8 fuel pump, support for over-the-air software updates, and repositioned oil and dual fuel filters for easier maintenance.
While some Ram truck enthusiasts have welcomed these updates, one change has sparked debate — the switch from traditional grid heating technology to glow plugs.
