10 Diesel Engines Packing the Most Horsepower You’ll Actually Care About

5. Cummins 6.7L ISBe Turbo Diesel — Ram’s Heavy Lifter

In production since 2007, this Cummins engine powers Ram 2500 trucks with 420 HP and 1,075 lb-ft torque. It’s a diesel that just keeps going, capable of towing 20,000 pounds and more, and still going strong into 2025.