by light output do you mean brightness? if so then no; with the killer what you loose is the DRL and the low beams staying on at night when you hit unlock at night; see the lights staying on with unlock (peremiter lighting) operates at the same power as the DRL's and will cause your HID's to flicker over time. The module just increase the power to 100 percent which is needed to power the ballist to power the bulb. the killer is basically 0% power for the DRL's
let us know if your are still confused in any way:thumbsup: