[nitrostarter]

4s is more than necessary.

5s, maybe for a big track with higher speeds and longer straights.

Turning down the EPA is non-sense. Set the car up right. Turning down the EPA is limit the ESC and thus making it always have to work hard to know the motor timing and when to send power. Where as, when you have the ability, the ESc is now capable of working less, or "thinking" less and should therefore run cooler.