no. see your car is pcm controled meaning your pcm decides what your chargeing voltage will be. mine would go between 13.2 - 15.0 and everywhere in between just diving down the road with everything off. it just picked its own voltage. which is no good if u are driving around at 13.3 and turn your system up haha. the adjustable voltage harnes lets u set your voltage at say 14.8 and it will be between 14.8 all the time. not taking into account for voltage drop. so basicly more voltage all the time. and if you wanted to run 16 or 18 volt systems you just turn the dial and voltage will go up. (DO NOT DO THAT UNLESS YOU KNOW WHAT IT WILL TAKE TO RUN !^ OR !* VOLT SYSTEMS)