What can you do about the REX NOISE???

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New member
Sep 7, 2021
Ok so I understand that the REX is super loud when it turns on to power the battery. But this noise is way to loud that its sometimes embarrassing so drive in a quiet neighborhood lol

No one has figured out how to eliminate or at least help with the sound?

I just got my 2018 BMW i3S REX and loving it! Except the noise of course.

I have noticed that if I'm at a stop light next to a large panel truck, or driving on a street with buildings closer to the curb, there seems to be an amplified sound bounce-back to the car, that people outside the car really don't hear. From a physics textbook - "Sound waves reflecting off of parabolic surfaces concentrate all their energy to a single point in space; at that point, the sound is amplified". maybe that is what is going on???
And now I'm wondering if anyone makes an aftermarket exhaust for the i3 with a 3" tailpipe for a "free-er flowing exhaust" (and more noise). :lol:
Use it on highway only, let the wind and road noise drown it out. I've learned that the first day, can't even tell its running over 25mph
My advice is to make sure you have Hold State of Charge activated, if you haven't already. That way you can choose when you're going to use the REX and when to drive in normal stealth mode.

John Francis
Rolla, MO