Claim: Detroit Diesel is a company.

Detroit Diesel Corporation -LRB- DDC -RRB- is an American diesel engine manufacturer headquartered in Detroit , Michigan , United States and a subsidiary of Daimler Trucks North America , 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 , 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 .