Without corrosion, the available starter current can be calculated with Ohm's Law:

The available starting power can be calculated from the power relationship.

How would these values be changed if there was a terminal resistance of 0.1 ohms?

With corrosion, the series resistance is 0.1 + 0.04 = 0.14 ohms.

The total power is

but not all of this reduced power goes to the starter.