RAM Legends: The Legacy of Clessie Cummins

2008 Ram Cummins Engine

The story of the Cummins engine is one of diesel determination. Its partnership with Chrysler Dodge was epic. The eventual installation of Cummins engines in RAM Trucks was a game changer.

A diesel-determined epic game changer.

An Invention’s Infancy

Clessie Cummins came from a farming family in Indiana, though it was clear early on that farming was not in his future.

Never completing more than an eighth-grade education, Cummins was always mechanically inclined with a penchant for inventing and creating.

Local lore insists that, at the age of eleven years old, Cummins built his own steam engine that his father then used to power the family’s farm.

Arguably the last connection Cummins had to farming, though he would go on to influence the agricultural industry, but in a very different way.

Not surprisingly, Cummins went on to become a mechanic and chauffeur, working for an affluent banker named William Irwin who would eventually become one of Cummins most important financial backers.

In 1918, Cummins encountered his first diesel engine, imported to the United States by the Dutch manufacturer, Hvid.

After securing a licensing deal to build Hvid engines Stateside, Cummins founded the Cummins Engine Company in 1919, and brought the diesel internal combustion engine technology, first invented by Rudolph Diesel in 1898, to commercial reality.

Failure Breeds Innovation

Cummins sold his engines through Sears Roebuck catalogs, unwittingly setting himself up for failure. Even back then, Sears had a return policy.

Farmers, trying to make a buck and save a buck, used the Cummins engine for a season and then returned them for a full refund. Backers like Irwin never realized a profit from this arrangement, but fortunately did not give up on Cummins either.

This setback actually inspired Cummins to consider the possibility of diesel engines in motion. Up to this point, they were stationary machines, primarily reserved for agricultural purposes.

Wheels in Motion

Cummins successfully installed his diesel engine in a 1926 Packard Touring sedan and trekked from Indiana to New York City where he planned to unveil his diesel engine-powered car at the 1930 New York Show.

After completing the 800 mile trip on 30 gallons of fuel, with an impressive (even for today) fuel economy of 26 mpg, Cummins was turned away from the New York Auto Show for being an unregistered participant.

Undeterred, Cummins tried to gain entry into the auto show in Atlantic City, but was also turned for having failed to register. So, he rented a small space across the street and ultimately drew a larger crowd than most of the show’s proper registrants.

With the success of that initial introduction to diesel-powered automotive engines, Cummins considered another possible installation.

Truckin’ It

Cummins upped the ante with his next experiment, this time installing his own Model U diesel engine into a 1931 Marion truck.

Embarking on an incredible journey, Cummins drove that truck from New York City to Los Angeles, covering more than 3,000 miles in ninety-seven hours.

It’s important to realize that the American Interstate Highway System had yet to be created and, in fact, would not be created until 1956 when President Eisenhower signed the Federal Aid Highway Act, the largest public works initiative in the history of the country.

Of course, Cummins diesel engines would power much of the heavy equipment that would create those highways. Until then, Cummins explored more testing grounds.

Bus Stop

After successfully completing the New York to Los Angeles route by truck, Cummins tried out his diesel engine in a bus, and tested it on the same New York to Los Angeles journey.

The trip took ninety-one hours with the bus reaching maximum speeds of 65 miles per hour. This was astounding and signaled a serious step ahead for transportation.

At its top speed of 65 mph, Cummins’ bus was faster than the passenger trains of the time. Between the cross country journey via increasingly efficient modes of transportation, it is easy to see how Cummins did more than invent an effective engine.

He really revolutionized our transportation system, challenging what was available with what was possible. To that end, Cummins installed a lightweight, six-cylinder diesel engine in an Auburn 851 sedan.

Getting 40 miles per gallon and able to reach top speeds of 90 miles per hour, this was a promising union between Cummins ingenuity and an established passenger car manufacturer.

Unfortunately, the union was short-lived as Auburn went out of business one year later in 1936.

Race to the Finish

Fascinated by race cars, and aware that the racing industry was an excellent marketing tool for his engines, Cummins entered a diesel-powered Duesenberg in the 1931 Indianapolis 500.

After a seventeenth-place qualifier, Cummins’ car finished in thirteenth place, but never needed a single pit stop.

In 1934, Cummins tried for a better outcome, this time racing two cars. One, equipped with a two-stroke engine, the other with a four-stroke.

The result led to a decisive moment in Cummins’ engine development. Although the two-stroke finished well before the four-stroke, it came in smoking so badly that the pistons seized and Cummins resolved to only develop four-stroke engines from that day forward.

Cummins continued participating with the Indianapolis 500, but never actually realized his goal of placing first in a race and after 1952, diesel race cars were no longer seen on the Indy racetrack.

Rubber Meets the Road

Although Cummins continued to work for a variety of companies and developed other automotive inventions.

By 1984, Cummins engines had evolved across the agricultural, industrial, and on-highway industries, powering combines, tractors, road graders, loaders, cranes, and crawlers.

But the real innovation came in 1989 when Cummins signed a contract with the Dodge Truck Division, installing Cummins B-Series 5.9-L 12V engines in the Dodge RAM truck series.

The original engine produced 160 horsepower with 400 lb-ft. of torque, better than any diesel competitors on the road. For the first time, a light-duty truck was equipped with a medium-duty diesel engine.

No other diesel truck on the road at the time had an engine with this gross vehicle weight rating that could compete with the Cummins B-platform 66,000 pound limit.


That legacy, and reputation for innovative durability and reliability, has cemented Clessie Cummins in automotive history and established his Cummins engines as invaluable to industry and transportation.