The Daimler-Benz DB 601 was a German aircraft engine built during World War II. It was a liquid-cooled inverted V12, and powered the Messerschmitt Bf 109, Messerschmitt Bf 110, and many others. Approximately 19,000 601's were produced before it was replaced by the improved Daimler-Benz DB 605 in 1942. The DB 601 was basically an improved DB 600 with direct fuel injection. Fuel injection required power to be taken off the drive shaft, but in return, improved low-RPM performance significantly and provided aerobatic performance in maneuvers where early versions of carburated engines like the British Rolls-Royce Merlin would lose power when the carburetor float bowl ran dry. The 601's fuel injection provided a significant boost in performance which its competitor, the Junkers Jumo 210, did not match for some time. By the time the fuel-injected 211 arrived, the 601 had already cemented its place as the engine for high-performance designs like fighters, high-speed bombers, and similar roles. The 211 would be relegated to bombers and transport aircraft. In this respect, the 601 was the counterpart to the Merlin engine of roughly the same size and power. The DB 601Aa was licence-built in Japan by Aichi as the Atsuta, by Kawasaki as the Ha40, and in Italy by Alfa Romeo as the R.A.1000 R.C.41-I Monsone. Development Based on the guidelines laid down by the German "Reichverkehrsministerium" (Reich Ministry of Transport), in 1930 Daimler-Benz began development of a new aero engine of the displacement class: a liquid-cooled inverted-vee 12-cylinder piston engine. This was designated F4, and by 1931 two prototypes were running on the test bench. These were followed by the improved F4B, which became the prototype for the DB 600. In 1933, Daimler-Benz finally received a contract to develop its new engine and to build six examples of the DB 600. For the year after, the DB 600 was the only German aero engine in the 30-litre class. In total, 2,281 DB 600s were built. The DB 601A-1 was a development of the DB 600 with mechanical direct fuel injection. Like all DB 601s, it had a 33.9 litre displacement. The first DB 601A-1 prototype, designated as F4E, was test run in 1935, and an order for 150 engines was placed in February 1937. Serial production began in November 1937, and ended in 1943, after 19,000 examples of all types were produced. Variants DB 601 A-1 Up to at sea level