Noticed when I got our new S cab that the tail pipe had soot in it. Also, looked around the lot and noticed most every MINI had some soot in the pipe. Was wondering if MINIS are set rich at the factory to aid in cooler running. Any thoughts?

 

My 2006 R53 has done it since new. I just use an old towel and wipe both

the inside and outside of the pipes each day.

 

Thanks. I though that may be the case. Just wanted to see if others had noticed the same issue and not just the batch of new ones that were at the dealership. Also, thought they may be set to run rich during break end but if yours is still doing it than it is just the standard fuel mixture setting. Just more then any other car I have had but can understand why knowing what I do about engines. Most cars are set rich to keep temps down and most "tunes" lean them out however, if leaned too far you can burn a piston. I would imagine the designers know the heat build up in MINIS and set them to run extra rich.

 

Forced induction motors are run rich....
A rag with some WD-40 does a great job wiping it off....

 

The short answer is "no"--rich mixtures cause higher emissions and worse fuel economy, which is a big no-no for auto makers. Under most circumstances, particularly idle and cruise, all modern cars run at the "stoichiometric" mixture. This is neither rich nor lean, and is the mixture range where the catalytic converter works best.

All cars will run at least slightly rich under WOT (Wide Open Throttle), and at warm-up, and on engine start. How rich they run will vary from model to model and depending on the exact circumstances. For instance, as was already said in this thread, Turbos tend to be run fairly rich at WOT to cool the intake charge and the combustion chamber somewhat.

So the longer answer is "mostly no, but a little bit yes."

 

An even shorter answer, Yes they run rich!

 

Yeah it's completely normal. When I bought my used '08 MCS I could tell know one had cleaned the pipes maybe ever. Took a good brushing to them and now just a mist of soot to clean during the weekly washes...

 

Too bad this short answer is the wrong one. Slave nailed it.

- Mark

 

Stock Ecu on the MCS 1st Gen. is set to run slightly rich.

 

My 335i had the same soot on the tail pipes and my MCS does too. You have to keep after it though because as Bmont82 said, it can get tough to get off if you let it go too long.

 

Thanks. I thought I was correct but not having MINIs before, wanted to make sure. Understand the cooling effect and makes sense. I appreciate the input as it is running richer then my other vehicles. It did wipe off easily given that the car is new.

 

With catalytic-converter equipped cars, you really can't use tailpipe color as an indication of mixture richness. As long as the tailpipe coating is dry and sooty and not oily/sooty, everything's fine.

 

Of course, one call always get a tuner to monkey with the MAP...

Caveat emptor, and soot yourself!

(Oh Lord I just slay myself sometimes)...

More coffee please?

Charlie

 

Thanks again for the posts. Interesting to get to know each new car. Hopefully, the rich mixture will not kill the cats before their time. I guess the worst thing about that would be a CEL.

 

It's not just the "S" either. My 2002 Cooper leaves the tailpipe black in a few hundred miles.

 

I know my MINI is running rich because I can smell it and it burns my eyes when I am at the back of the car while it is running. Mostly because it is tuned and catless.