5.9L Cummins vs. 6.7L Cummins

Dodge Diesel - Old vs. New

Pumping out over 800 lb-ft of torque, the latest version of the Cummins turbodiesel has come a long way. The 5.9L 12v was the first diesel to be put into a Dodge truck, and the relationship between Dodge/Chrysler and Cummins has been strong since. Both the 5.9L and 6.7L are inline 6 cylinder engines, the only 6 cylinder turbodiesel that has ever been offered in the light duty truck market (Ford & GM diesels have always been V-8 configuration). The 12v helped earn Cummins a reputation of strength and reliability, though the more recent 6.7L has suffered many longevity/reliability concerns relating to the engine's emissions systems. Obviously, the simplicity of a mechanically injected, non-emissions controlled turbodiesel still has its perks.


Cummins 6BT

1989 5.9L 12v Cummins

6.7L Cummins

2011 6.7L Cummins ISB


5.9L 12v Cummins Turbodiesel

6.7L ISB Cummins Turbodiesel

Years of Operation:

1989 - 1998

2007.5 - Current


5.9L, 359 cubic inches

6.7L, 409 cubic inches



Turbocharged & intercooled, VGT


Direct injection, mechanical injection pump

Direct injection, high pressure Bosch common rail

Block/Head Material:

cast iron/cast iron

cast iron/cast iron


160 hp @ 2,500 rpm (1989)

350 hp @ 3,000 rpm (2011)


400 lb-ft @ 1,600 rpm (1989)

800 lb-ft @ 1,600 rpm (2011)


You may also be interested in the following articles:

Ford Diesel Old vs. New

GM Diesel Old vs. New

Power Stroke vs. Cummins