12 AWG or 10 AWG?

[lior9999]

Life's biggest question, really. I know FIRST states the minimum wire gage for 40 AMP motors (i.e. big SIMs) is 12 AWG, but I've always been weary of this. Here is a current limit vs wire diameter standard chart:

http://www.powerstream.com/Wire_Size.htm

The maximum current for chassis wiring using 12 AWG is 41 amps, which I guess is okay. But with current spikes and the likes...I don't know.

Is the voltage drop on 12 gage wire not that big a deal? What's your take? What does your team use and why?

Thanks for any and all input.