In a Hot Rod?!?! (Image/OnAllCylinders)

It was originally designed and built for commercial trucking applications.

But then Chrysler dropped it into Dodge Ram pickup trucks in 1989. Legions of people have been in love with the 5.9-liter, inline-six Cummins turbo diesel engine ever since.


General Motors and Ford had already entered the diesel marketplace by the time Dodge partnered with Cummins to put the 5.9L turbo diesel in the 1989 Dodge Ram.

Because of its uniqueness and incredible efficiency, it became very popular with light- and medium-duty truck owners. The turbo diesel I6 could double the fuel mileage of many of its eight-cylinder competitors. The popular 12-valve engine was replaced by an even more-popular 24-valve version in 1998.

Emissions regulations adversely affected Big Three truck manufacturing across the board.

The venerable 5.9L was retired in 2007 in favor of a 6.7L version of the popular Cummins B-Series engines.


Inline six cylinder turbodiesel 24V

Horsepower – 235-325 @ 2900 rpm

Torque – 460-610 ft.-lbs. @ 1600

Stroke – 4.72 inches

Bore – 4.02 inches

Compression – 16.3:1, 17.2:1

Top Aftermarket Upgrades

According to Summit Racing, these Cummins 5.9L I6 parts are the most readily available (number of options as of 1/17/2014 in parenthesis):

Editor’s Note: This series counts down the Top 10 engines of all time—see how the voting was done by reading our initial post.

Author: Matt Griswold

After a 10-year newspaper journalism career, Matt Griswold spent another decade writing about the automotive aftermarket and motorsports. He was part of the original OnAllCylinders editorial team when it launched in 2012.