its odd, outside the car i dont know about, but in the car at about 1800 theres a sort of boom from the exhaust, if i drop down to 1500 it goes away, if i go over 1800 it goes, but if you keep it around 1800 imo its a bit boomy, same as when you back off, it reminds me of a aftermarket exhaust i once had (obviously its standard though)