5.9L Cummins vs. 6.7L Cummins

The Evolution of the Cummins Turbodiesel


First introduced for the 1989 model year in Dodge pickups, Cummins' 6BT produced 160 horsepower and 400 lb-ft of torque; class leading output. 27 years later, torque and horsepower have more than doubled in Cummins equipped Ram pickups. While the 5.9L was ultimately retired following the 2007 model year, a technologically advanced 6.7L model continues its legacy.



1989 5.9L 12v Cummins

2016 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)

385 hp @ 2,800 rpm (H.O. model)


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

900lb-ft @ 1,700 rpm (H.O. model)