A few years back, i ran a 2500d in a stock civic electrical, with very little fusing (40 amps). It is a very efficient amp @ 1 ohm. @ .5 it gets very current hungry.
i have it on my 130 alt and stock battery rite now.with 1/0 goin into 4awg its alrite @2 ohm rite now.just want to get it to run very strong and have it @ 1 ohm