Being relatively new to the mini world , but now will never drive anything but an MINI!!
I noticed that both my car and my wife's (2015 r57 MCS and 2015 r60 all4 CM) have a sooty exhaust, I always learned growing up that a black deposit in the exhaust means a bad air fuel mixture or incomplete combustion and that a clean exhaust with condensation dripping from it is ideal .. My 2003 Chevy truck exhaust is fifer licking clean and both of the minis have enough black soot to disguise your face in a combat field ... Why?

 

Don't worry about it, all Mini's have sooty exhausts..

 

But this is a signal of a very poor combustion!! A clean combustion should produce co2 , some co and h2o that's it as far as I am concerned

 

Lots of threads on this -

https://www.northamericanmotoring.co...k-n-sooty.html

 

Yep, very typical.

I just try to clean it so the black carbon does not build up. Try some polish or some car soap. Then if its really bad non scratch pad and soap. I actually cleaned many like this on my own MINIs.

HMP from CG works great also.

https://www.ecstuning.com/Search/SiteSearch/Metal_Polish/

 

+1

Very common and talked about a lot. Great thread linked. I posted a product in that thread that you can use to help clean them off. I have used it for many years with great results.