The company manufactures heavy-duty engines and chassis components for the on-highway and vocational commercial truck markets.

Detroit Diesel's product line includes engines, axles, transmissions, and a Virtual Technician service.

[24] The trucks used engine ECU software to engage pollution controls during the 20-minute lab tests to verify compliance with the Clean Air Act, but then disable the emissions controls during normal highway cruising, emitting up to three times the maximum allowed NOx pollution.

[24] In 2016, Detroit Diesel agreed to pay U.S.$28.5 million to resolve violations of the U.S. 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.