The importance of an adequate exhaust system on a vehicle is never to be underestimated, especially on an aftermarket project.

And even if we are to put aside the improved airflow and extra power a custom exhaust brings, we are still left with the pure noise it delivers.

Battles between BMWs equipped with aftermarket exhaust systems are quite common among enthusiasts, and while most would agree that there is a definite difference between revving your engine in neutral and really giving it all on the road, sometimes it’s easier to just let loose in a parking lot.

Gathering a few BMW M135i, a sound-off battle royale was organized, just to see which tuner provides the most noise with their respective product. Measured in decibels, there was not that big a difference, but overall BCS was the loudest. If It were up to me, decibels wouldn’t be the way to go, but rather a 3 person jury.