Ram is ready to stump the Earth with a new model that fills a key void in its Heavy Duty lineup. The 2023 Ram 2500 Heavy Duty Rebel slots between the Big Horn and Power Wagon, but unlike the latter which settles for the 6.4-litre HEMI V8 (410 horsepower, 429 lb-ft. of torque), it is also available with the 6.7-litre Cummins turbo-diesel six-cylinder engine, which delivers 370 horsepower along with 850 lb-ft. of torque.