[Badpuppy]

Certainly nothing wrong with heavier wire size, but it has diminishing returns. As Penthode points out, the major loss is in switch contacts and connectors. Which makes a case for converting to 12 volts. Since 12v components use half the current of 6v, the voltage drop across the same network is also half, which produces only 1/2 x 1/2 = 1/4 the power loss.