I put it on my Ram 2500 6.4 petrol 2017. Sounds incredible! no drone in the cockpit, with or without a resonator. just removed it. My truck is definitely louder, it has the louder sound of a "male" truck but not too loud. FYI I have found that these cat back systems mostly get the horsepower increase at the expense of the muffler as the stock muffler is very limited. I didn't want to spend $800 so I just bought a silencer and removed the resonator. As I said. THAT SOUNDS FANTASTIC. KNN also had a cold air intake drone with this storage system. After installing the muffler the noise went away.