Originally Posted by SouthArk370Z

I wouldn't recommend it. 4 AWG wire is only rated for about 90 Amps while 1/0 AWG is rated for about 170 Amps. The voltage drop (and heat generated) will be greater at high loads (eg, starting).



The conductor material is not important but you will have to use a larger conductor if you use aluminum instead of copper. The total resistance of the wiring run is the critical factor - bigger wire has less resistance per foot. You can use "exotic" stereo wiring, but it's expensive and not cost-effective for the minuscule gains.



The more strands in the conductor, the more flexible the wire will be (assuming the same insulation). 1/0 AWG with a solid conductor is VERY stiff and difficult to install; 1/0 AWG welding cable (~1000 strands) is down right limp.