Initially underpowered with an Allison V-1710 engine, it rapidly achieved dominance when powered by the Packard V-1650 engine made under license from Rolls-Royce.
The aircraft's initial performance was limited by the Allison V-1710 engine; however, its power output improved significantly after being equipped with the Packard V-1650 engine, which was manufactured under license from Rolls-Royce.