Clessie Lyle Cummins December 27, 1888 - August 17, 1968 was the founder of the Cummins Engine Co. He was an entrepreneur who improved on existing diesel engines, created new diesel engine designs, was awarded 33 United States patents for his inventions, and set five world records for endurance and speed for trucks, buses and race cars.

Cummins began his career as a rural Indiana farm boy, and had no formal higher education beyond the eighth grade. In the 1920s Cummins went to work for a banker named William Irwin in Columbus, Indiana, as a chauffeur and mechanic.

In 1919, Clessie Cummins founded the Cummins Engine Co, Inc (now Cummins, Inc). At the time of its founding, Cummins developed the first engine as licensee of R.M. Hvid Co. This engine was a 6-horsepower model designed for use on the farm.

Cummins' former employer, Irwin, invested a great deal of money in Cummins' company. However, Irwin was not satisfied with the company's profits and threatened to cease investing. Sales of diesel engines to farmers through the Sears-Roebuck catalog were not generating significant profits, partially because farmers would purchase and use the engines during the harvest period and then return them to Sears.

Clessie Cummins secured a Packard limousine (a vehicle with a large engine compartment) and fitted one of his best engines into it with 3/8-inch to spare. He and an assistant drove the vehicle to the 1929 auto show in New York City using $1.39 worth of diesel fuel. The pair arranged for publicity along the way, but when they arrived at the show they found that they had been banned from any presentation. Cummins proceeded to rent space across the street from the Auto Show, and the "$1.39 for fuel, Indy to NYC" auto become a popular feature of the show (despite not technically being included in it).

Cummins' times with the engine company continued to be tumultuous even after this success, but money was being made. Cummins' first successful engine design, the Model F [(1924)], was originally used for marine applications, but came to be used in other applications. In 1931 Cummins entered the Indianapolis 500 with a self-built (3,389 pound, 361 cubic-inch) four cylinder, three-valve, 85 horsepower, Model U marine diesel that he installed into Model A Duesenberg. The Cummins Duesy averaged 86 miles per hour and completed the race on 1 tank of fuel, without any pit stops! [Car & Driver Magazine. October 2003]

World War II ensured the success of the fledgling company: the American military bought every diesel engine which could be produced in preparation for an Allied invasion of continental Europe.

Legacy

In 1955, Cummins was eased out of the company he created, retiring from the position of Chairman. He had managed to hold onto some key patents and formed Cummins Enterprises Company later that year. He moved on to work for the Allison Engine Company in California.