I have a/c so I guess that wouldnt work out for me. Why? Well, I just bought my X and the alt. is brand new (not sure what amp. it puts out). For my stereo I need a HO alternator and I dont want to return the brand new one as a core, so I figure I keep it, pay the core charge for the new one and have 2 running, then have no charging issues to worry about. Also this way I dont have to get an expensive one.