Originally Posted by
the727kid
You should be fine with 4 gauge to the back. But that 0 gauge will help voltage at the amps. I would only do the big 3 in 0 gauge. Most factory wiring is already 4 gauge.
Ill take the make/model of a car that runs 4ga alt -> bat wire. thats gonna be my next vehicle.
0ga compared to 4ga over the 2-3ft you will need for the big three will make absolutely no difference since your alternator cannot produce enough power to bring a 4ga wire to capacity... The ground wire should be as big as you can make it though.