Detroit Diesel Corporation (DDC) is an American diesel engine manufacturer headquartered in Detroit, Michigan, United States. It is a subsidiary of Daimler Trucks North America, which is itself a wholly owned subsidiary of the German Daimler 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,[1] more than 1 million of which are still in operation worldwide. Detroit Diesel's product line includes engines, axles, transmissions, and Virtual Technician.

Detroit engines, transmissions, and axles are used in several models of truck manufactured by Daimler Trucks North America.

In 2016, Detroit Diesel agreed to pay US$28.5 million to resolve violations of US federal Clean Air Act. The company sold 7,786 heavy-duty diesel engines, which were assembled approximately 80% complete in 2009, including the crankshaft, block, pistons, and connecting rods, the short block engines were stored temporarily and completed the remaining assembly in early 2010 for use in trucks and buses of in model year 2010.[7] These engines were alleged not to comply with stricter 2010 emission standards.[7]

Stewart & Stevenson