[Steve Miller]

I need to buy a new diffuser that will work with quad exhaust. I am finding a ton for the F10 M5 but see conflicting data on fitting. I have a 2014 535i M sport with dual single exhaust and am installing the mufflers with quad tips from an M5

In some places, it says the M5 diffuser will be an easy replacement & others say you need an adapter.

Can someone that has done this please let me know. Thanks!

[spielnicht]

OEM M5 diffuser (or replicas) will need an adapter to work on non-M5 cars.

https://www.ecstuning.com/b-genuine-...r/51128053585/

Aftermarket M5-style diffusers (generally made for the 550i) do not need the adapter and will just mount on the bumper.

Look at this thread for more clarity between the two options:
https://f10.5post.com/forums/showthread.php?t=1794885

[GrabacrOne]

The M5 adapter is needed for an OEM solution, but some have just cut the stock adapter to fit the M5 diffuser. I just went with the M5 adapter and everything lines up perfectly.

One thing to note, the comfort access and TPMS/RDC module locations are swapped (left/right) on the M5 wiring harness, so the pocket in the M5 adapter won't work to hold the modules on our cars. So I used some 3M double-sided tape and zip ties to secure the modules on the backside of the adapter, moving them up and away from any contact points and the elements.

If you have comfort access, you also need to move over the sensor for the kick-to-open trunk to the M5 adapter, but the positioning again will be flipped compared to what the M5 has. If you go with aftermarket or even OEM M-Performance carbon diffuser, you most likely will lose the kick-to-open ability. I went with the OEM M5 diffuser to keep this feature.

Here is another thread with more details:
https://f10.5post.com/forums/showthread.php?t=950378

[Steve Miller]

Appreciate your help!