As title says, I have the 2015 IS 250 200 horespower engine. I wanted to know if it will be both noticeable in the cabin and outside and if so how noticeable? Never did this mod before, thinking about getting it done soon..

 

 

 

 

Don't know how it sounds on an IS250, but on my IS350 it sounds very good. It really doesn't make much, if any, noise when I'm just cruising. There's a tiny bit of "drone" in the cabin but that's only when you get on the gas pedal. I love how mine sounds. It's not obnoxious at all, and actually is a lot quieter than how a muffler delete sounded on my E92 335i. There is no way you would get a ticket from it, as someone mentioned above.

 

I drive an IS350 and I definitely hear the muffler delete. Passengers in the rear will definitely hear it, and my passengers in the rear seats couldnt hear me when using a normal talking voice. I definitely notice the drone, especially when doing Highway driving. It boils down to if you mind it or not. It's certainly reversible if you ask your muffler shop to let you hang onto the mufflers, that way if you decide to go back, they can just weld them back in.