The 2004.5–2007 Cummins 5.9L marine engine delivers strong torque, improved efficiency, and proven reliability. This updated 24-valve inline-six runs the Bosch high-pressure common rail fuel system for better throttle response, cleaner emissions, and precise fuel use.

A cast iron block, forged crankshaft, and reinforced internals handle heavy loads and long hours on the water. Upgraded injectors and electronics enhance performance in both commercial and recreational vessels. Marine-grade materials and a closed cooling system protect against saltwater and heat.

Power your boat with trusted Cummins strength—choose the 5.9L marine engine built to perform.