Cummins 6.7-Liter Turbo Diesel: How Much HP & Torque Can The Next-Gen Engine Produce?

Since 1989, RAM (earlier Dodge RAM) has been using engines made by Cummins on their popular pickup trucks. The journey, which started with the first generation 5.9-liter 160 hp turbo diesel, has witnessed several updates over the past several years.

In 2007, Cummins replaced the tried and tested 5.9-liter engine with a larger, 6.7-liter turbo diesel unit which remains part of Cummins' lineup as of 2025. In fact, the company recently launched the latest iteration of the famed 6.7-liter Turbo Diesel engine, incorporating several new features and enhancements. It is also slightly more powerful than the older model it replaced, albeit not by much.

Besides making slightly more power, the refreshed 6.7-liter engine is claimed to be the most advanced variant of the diesel pickup engine so far. On the newly announced 2025 RAM 2500 and 3500 Heavy Duty, this engine is mated to a new column-shifted TorqueFlite HD eight-speed transmission, which aids in an enhanced towing capacity of 36,610 pounds and an improved 0-60 mph time of 6.9 seconds, compared to 8 seconds with the outgoing engine.

The launch of these new trucks and the upgraded engine coincided with Cummins announcing that it had extended its agreement with Stellantis — RAM's parent company — through 2030. Simply put, Cummins will continue to supply engines to RAM for the foreseeable future.

Since its 2007 launch well over 17 years ago, the 6.7L engine has undergone several updates. In its original 2007 iteration, the engine made significantly less power than today. The 2007 year engine produced 350 hp of power and made 650 lb-ft of torque.

In 2013, the power figures climbed to 385 hp, and 850 pounds-feet torque. In 2019, Cummins finally breached the 1,000 lb-ft mark with a 400 hp variant of the same engine. The last time the engine was updated was in 2021, when Cummins added 20 more horses to the engine, taking the power output to 420 hp and enhancing the torque figures to 1,075 lb-ft.

For the 2025 iteration, there is an expected bump in the power figures. While power has gone up by a nominal 10 hp (430 hp), the torque figure — at 1,075 lb-ft — remains unchanged. Even with the nominal jump in power figures, the 2025 Cummins 6.7-liter Turbo Diesel is the most powerful engine to make it to the RAM 2500 and 3500 series trucks.

Besides making more power than before and mated to a new transmission, the refreshed 6.7L engine also features enhancements that aid in easier serviceability. Buyers can also expect easier cold starts on trucks with the new engines thanks to integrating a new glow plug system that replaces the older grid heater system. It remains to be seen of the latest iteration of the Cummins 6.7 liter turbo diesel engine has what it takes to enter the list of the best Cummins diesel engines to ever make it to a RAM truck.