Cummins diesel engines are so ubiquitous and commonplace today, they're practically synonymous with the term "heavy duty diesel." The company's visibility and reputation only grew following the debut of the company's engines in the Dodge Ram truck line in 1989, introducing the company's products to the broader consumer market.

In its early days, however, the company was far from the global corporate titan it is currently. The combination of a trouble-prone licensed design from a Dutch diesel engine company and the Great Depression almost buried the company before it truly got its footing. The indomitable spirit of its founder, Clessie Cummins, kept the company alive, ultimately leading to the thriving business that is the Cummins we know today.

A Unique Relationship

Before the founding of his eponymous diesel engine company, Clessie Cummins worked as a chauffeur and mechanic for William Irwin, a banker in Columbus, Indiana. Although he had no formal education beyond the eighth grade, Cummins had a keen knack for the mechanical, which was noticed by Irwin. Legend has it that when Cummins was only 11 years old, he built his own steam engine from molten cast iron he poured into wooden blocks that served as molds. His homebuilt steam engine was used to pump water for his father's farm.

Cummins reportedly saw his first diesel engine around 1918, an imported engine from the Dutch manufacturer Hvid. Through correspondence and negotiations with local representatives, Cummins received a license to build Hvid engines for the U.S. market. After securing the licensing deal with Hvid, Cummins later negotiated to have his engines sold through the Sears Roebuck and Company catalog. However, an unforeseen loophole exploited by the farmers was Sears' return policy. Many farmers purchased the engines, used them for a season, and then returned them for a refund. Irwin, who was Cummins' major financial backer, was obviously not thrilled with the situation, and encouraged Cummins to continue to improve the design and reliability of the engines.

Rolling Showcase

Wanting to move beyond merely stationary, agricultural engines, Cummins was convinced diesels had great potential as powerplants for cars and trucks. To demonstrate their feasibility and efficiency, he installed one of his engines into a 1926 Packard Touring sedan, which he drove from Indiana to New York City with the intent of presenting it at the 1930 New York auto show. The car covered nearly 800 miles having used only 30 gallons of fuel -- an average of 26 mpg, an astoundingly efficient figure for the day. Because he was not officially registered as an exhibitor at the show, Cummins was turned away. The scenario repeated in nearby Atlantic City, where Cummins also showed the car. This time, he rented space across the convention hall to display the car and ended up being an even bigger attraction than most of the official exhibits at the show.

In 1931, Cummins staged another one of his famous public exhibition drives using a Marion truck equipped with one of his Model U engines. The truck drove from New York to Los Angeles, a distance of over 3000 miles in only 97 hours, more than two decades before the construction of the Interstate highway system.

After his successful truck demonstration run in 1931, Cummins followed up with another New York to L.A. run with a bus, which completed the journey in 91 hours, and achieved speeds up to 65 mph. The time proved faster than that of passenger trains of the day, and was a foreshadowing of the impact the interstate highway system would have in the decades to come.

Wanting to follow up his success with the Packard, in 1935 Cummins swapped a new lightweight six-cylinder diesel into an Auburn 851 sedan, which achieved an incredible for the time (and good even for today) 40 mpg. The car also reached an equally impressive top speed of 90 mph. Cummins hoped for a long-term relationship with the automaker, but Auburn went out of business only a year later.

Off To the Races

Realizing that racing was good publicity, Cummins entered a diesel-powered Duesenberg in the 1931 Indianapolis 500. The car qualified 17th and finished 13th. More remarkable than its respectable finish was the fact that it completed the entire race without a pit stop.

In 1934, Cummins returned to the Indianapolis 500 with two cars. One was a two-stroke diesel, and another was a four-stroke. Both utilized Roots-type superchargers. Although the two-stroke finished ahead of the four-stroke, it was smoking badly toward the last part of the race. After it had finished, the engine was so hot it seized the pistons to the block. From that day forward, Cummins has exclusively made four-stroke engines.

Cummins would go on to be an active participant in the Indianapolis 500 for decades, but a first place finish would elude Clessie and company. Undeterred, he entered a race car known as the Green Hornet for its distinctive paint job powered by a Model JS engine producing 340 hp in the 1950 race. The car qualified in 32nd place, and finished 29th. In 1952, Cummins took a first place qualifying position. The car ran strongly, but fell back during the course of the race, finishing 27th. A post-race inspection revealed that the turbocharger inlet on the car was clogged with rubber tire particles from the track. This would be the last time a diesel-powered race car competed at Indy.

Cummins retired from the board of directors in 1955, and went on to found his own company, Cummins Enterprises. He had been working on an experimental exhaust brake prior to his retirement, and later partnered with the Jacobs Chuck Company to create another icon of the diesel world, the famed Jake Brake exhaust brake. He later worked briefly for the Allison Aircraft Engine company in California. Clessie Cummins Sr. died in 1968. His son, Clessie Lyle Cummins, has written several books, including "The Diesel Odyssey of Clessie Cummins," a biography of his father and the company he founded.

Racetrack dominance eluded Cummins for many decades. The closest the company got to an Indy 500 win was the 1987 race, which Al Unser won in a Cosworth-powered car that used a turbocharger from Holset, a British manufacturer Cummins had acquired a decade earlier. Still, the company has retained dominance of the commercial diesel market, holding more than a 40-percent market share among Class 8 trucks for 2012 year to date.