Early carrier fighters trade engine power against weight and agility

Navies wanted simpler aircraft logistics, but different performance requirements pushed them toward different engines. Before improved streamlining offered greater gains, power relative to weight strongly governed an aircraft's maneuverability. A larger engine supplied more power while also adding mass, so designers could seek improvement by lightening the airframe instead. The 1MF combined about 300 horsepower with a loaded weight of 2,822 lb, while the B1M carried nearly 6,000 lb on 500 horsepower. A carrier-defense fighter needed to climb into position and turn sharply near its ship, making those qualities more valuable than sustained top speed in this period.