The Cleveland Diesel Engine Division of General Motors (GM) was a leading research, design and production facility of diesel engines from the 1930s to the 1960s that was based in Cleveland, Ohio. The Cleveland Diesel Engine Division designed several 2 stroke diesel engines for submarines, tugboats, destroyer escorts, Patapsco-class gasoline tankers and other marine applications. Emergency generator sets were also built around the Cleveland Diesel and were installed in many US warships. The division was created in 1938 from the GM-owned Winton Engine Corporation and was folded into the GM Electro-Motive Division in 1962. The engines continue in use today on older tugs.

Detroit Diesel Corporation (DDC) is an American diesel engine manufacturer headquartered in Detroit, Michigan. It is a subsidiary of Daimler Truck North America, which is itself a wholly owned subsidiary of the multinational Daimler Truck AG. The company manufactures heavy-duty engines and chassis components for the on-highway and vocational commercial truck markets. Detroit Diesel has built more than 5 million engines since 1938, more than 1 million of which are still in operation worldwide. Detroit Diesel's product line includes engines, axles, transmissions, and a Virtual Technician service.