The Cummins M Series engine is a straight six diesel engine designed and produced by Cummins. It displaces 10.8 litres (659.1 cu in). Introduced as the M11 in 1994, it was built on the previous L10 engine (same 4.921 inches (125.0 mm) cylinder bore, but a longer 5.787 inches (147.0 mm) piston stroke compared to the L10's 5.354 inches (136.0 mm) stroke).Later M11's received the electronic CELECT and CELECT Plus fuel systems consisting of a gear pump and solenoid controlled injectors.