The 5.9-liter Cummins is diesel royalty. It's the reason thousands of Ram trucks from the late '90s and early 2000s are still climbing hills, pulling trailers, and terrifying Priuses in the fast lane.
When it comes to heavy-duty diesels, enthusiasts and truck owners inevitably circle back to the best American diesel engines: Ford's 7.3L PowerStroke, Dodge's 5.9L Cummins, and GM's 6.6L Duramax. If ...