[Al Skierkiewicz]

This is one area that rookies will be behind the curve since the rules are a little misleading. The breaker size is set by rules so that the wire size is protected by the breaker rating. i.e. a 30 amp breaker should trip before the #14 wire it protects would melt.
Competitive teams will use the 40 amp circuit breakers and #10 wiring for the Chalupas and FP motors. I did see a few teams that used the 30 amp breakers on the big motors and wondered why. It could have been a weight saving idea but I didn't really see a need for that reduction in available power.