The GLS580 has dual mode exhaust. Does anyone know how it works? My GLS does not sound any different (louder) in any mode or when you accelerate hard it is still fairly quiet. My exhaust valves are closed at idle and that means the exhaust is directed through the smaller pipe only - without the valve. The GLS63 from what I have read is louder in "Sport" mode and has the same exhaust valve set up as the GLS580 on the larger Exhaust pipes. What is the experience of other 580 owners - does it get louder in any circumstances?

GLS580 exhaust valve

GLS63 exhaust valve

I noticed the same thing. My guess its activated by the throttle positioning sensor and by RPM. The car has an obvious low frequency rumble even at idle (on the outside). I ordered acoustic glass so there is little sound inside at any speed. Personally I think sound is perfect for a non AMG vehicle.

I test drove a 2021 GLS580 (USA model) and the exhaust had a very different sound when it was in the sportiest mode (not sure if it was “sport” or “sport+”). I was actually quite impressed with the growl and rumble it had. I think the average person can easily tell the difference in exhaust sound when switching between the modes and when the car is in “comfort” it was more like a typical SUV and was much more muffled.

PS: it’s worth noting that I currently have a BMW 535 that I installed the m-sport exhaust because stock exhaust was way to quiet for me.

Wondering if you ever figured this out? I got my 22 GLS 580 and Renntech looks like it has a module that allows for you to open/close it but I can't find any videos on if the sound actually changes since I can't find a video with the EVM installed to compare to. In Sport/Comfort etc nothing seems to change but hoping this module may be able to make use of it

Dont waste your money. All that switch will let you do is open the valve at will. You can do that by accelerating strongly. Regardless its not that loud. To get a loud farty exhaust you need the AMG exhaust.

same thing. I think exhaust is a little quiet. I'm wondering if i will swap the last muffler from gls 63 would help?

Could try a muffler delete.

I don’t want to have a super loud exhaust. All I want is get a bit louder, low tone sound. To be honest my older gl450 V8 sounds better.

A friend did a delete and it only made it slightly louder.

Not a V8 owner, but I really wish there were some performance muffler options for the 6 cylinder 450. Exhaust is silent and it could sound great.

Our 2021 580 starts with the flaps open but the closes them after a few seconds. You can hear the tone change in the vehicle and the flaps click shut if you're outside the vehicle. I assume they open under hard acceleration but I can't hear them change. Coders can force them open but I don't know if that includes the ability to close them as well as with the full AMG vehicles.