[citation needed] He and an assistant drove the vehicle to the 1929 auto show in New York City using $1.39 (equal to $24.66 today) worth of diesel fuel.

At that time, his employer and patron, Will Irwin, owned a controlling interest in the Purity Stores supermarket chain, in California.

Cummins convinced Irwin to install diesel engines in the fleet of trucks used to deliver food and staples to the stores.

[citation needed] The success at Purity Stores attracted considerable attention, and the over-the-road diesel truck industry thus came into being.

The Cummins Duesy averaged 86 miles per hour (138 km/h) and completed the race on 1 tank of fuel, without any pit stops.

[4] 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.

In 1960, the product was sold under the Jake Brake name by Jacobs Vehicle Systems, Inc. As he approached eighty years of age, he designed, built, and ran in his basement shop a new concept engine.

In 2022 Jacobs Vehicle Systems was acquired by Cummins Inc. bringing one of Clessie's inventions back to the company he originally founded.