The STP10NK80ZFP: The 900 mOhm Rds(on) at 4.5 A, 10 Vgs sets the conduction loss floor.
Thermal budget in the TO-220FP
The TO-220FP full-pack case limits dissipation to 40 W at the case. The 9 A continuous drain rating at 25°C case temperature derates above that point.
