i agree but it will be such a slight amount of drop that it really won't have much effect on anything. 1200w @ 13.8v is roughly 85A. OFC 4g is rated at being around 140-150A. it's not like hes pushing the wire to its capacity limits, so he really shouldnt be experiencing any noticeable dropThere will always be more of a drop in 4 gauge then 1/0, it's basic electrical theory.
