The Allison V-1710 is an American liquid-cooled V-12 engine that powered several Allied aircraft during World War II. It was the only US-developed engine of this type to see service in the war. The engine was designed by the Allison Division of General Motors in 1929, and first flew in 1932. It underwent several modifications and improvements over the years, reaching a maximum power output of 1,475 hp in some variants. The engine could be equipped with different propeller gearing systems and superchargers, depending on the aircraft requirements. It was used in the Lockheed P-38 Lightning, the Bell P-39N Airacobra, the Curtiss P-40 Warhawk, the North American P-51 Mustang, and other models. The Allison V-1710 was known for its reliability and durability, as well as its performance at low altitudes when turbocharged.