I=80 amps

R=0.0019 ohms

P=I^2*R=12.16 watts

That MOSFET has a maximum power dissipation of 250 watts. I tried to calculate the temperature (probably doing it wrong though).

Temperature=room temperature+thermal resistance*P=20+62*12.16=773.92 degrees celsius

That is extremely high. Am I calculating it right, or do I need a different MOSFET/multiple MOSFETs in parallel. I will be mounting 6*number of MOSFETS in parallel (1 right now) on an aluminium square tube that has a volume of 76 square centimeters (I may need a longer one, meaning more volume), so I guess you could halve the temperature (just a guess) because it will act as a heat sink. Thanjs,