The 2025 Ram HD is rumored to offer a single Cummins diesel engine with even more torque

Mopar Insiders posted in March regarding a rumored diesel engine for the 2025 Ram Heavy Duty lineup. Apparently, the truck brand would reduce its two 6.7-liter Cummins turbodiesel engine options to just one, and that engine would be more powerful as the most powerful engine on sale today. Currently, Ram 2500 buyers can get a standard-output (SO) Cummins diesel producing 370 horsepower and 850 pound-feet of torque, while 3500 buyers can choose a high-output (HO) version producing 420 horsepower and 1,075 pound-feet of torque. MID credits “sources within the company” with confirming a one-off engine for next year, insider hopes “this engine will outperform the current H/O variant, promising more power and torque “.

For context, Ford’s 6.7-liter Godzilla V8 diesel makes 475 hp and 1,050 lb-ft in base form, or 500 hp and 1,200 lb-ft in HO form. We suspect this is the one Ram is trying to get ahead of, with Ram still putting a huge effort into its Cummins brand and offerings, and having increased the diesel’s torque rating to 1,075 lb-ft in 2021, while mass of Ford delivered “only” 1,050 lbs. -ft. Chevrolet’s 6.6-liter Duramax diesel engine is available in just one trim, producing 470 horsepower and 975 pound-feet of torque.

As product insiders tell it, the main driver of Ram’s rumored strategy is a new eight-speed ZF Powerline automatic transmission. It’s supposed to replace the current Aisin-sourced 68RFE and AS69RC base transmissions, both of which are six-speeds. Developed for Class 5 through 8 trucks with engines maxing out at 1,000 lb-ft and GVWRs up to 57,000 pounds, we’re told its use in a heavy-duty pickup with a much lower GVWR will increase its torque ceiling. Transmission tech like “intelligent powershifts” is said to reduce fuel consumption by up to 10 percent, skip shifting is said to improve acceleration by up to 30 percent, and it reportedly weighs less than the six-speed it replaces.

The diesel engine switch would mean 2,500 buyers won’t be excluded from HO turbodiesel power, likely a common gripe submitted to Ram HQ since Ford’s HO Godzilla can be installed on any Super Duty. The engine overhaul comes with a refresh for the 2025 Ram HD lineup that will bring expected changes to the exterior and could install the 14.5-inch Uconnect 5 system in the cabin. The 6.4-liter Hemi V8 engine rated at 410 horsepower and 429 lb-ft will continue to be the base engine.