2003 - 2007 5.9L Dodge Cummins
The 2003-2007 5.9 Cummins remains one of the more respected common rail diesel platforms because the engine responds well to tuning and airflow upgrades without becoming overly complicated. Age is now the bigger problem on most of these trucks, especially around injectors, steering, suspension, and drivetrain components.
Turbochargers, fuel system parts, injectors, CP3 components, exhaust systems, steering upgrades, pistons, crankshafts, and transmission-related parts for 5.9 Cummins trucks are all grouped here. Once towing power and tuning increase, fuel supply pressure and transmission health become just as important as horsepower.