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, among others. The DB 601 was basically an improved DB 600 with direct fuel injection. The DB 601Aa was licence-built in Japan by Aichi as the Atsuta, by Kawasaki as the Ha-40, and in Italy by Alfa Romeo as the R.A.1000 R.C.41-I Monsone.