What colour’s your exhaust?

My totally standard E36 3.2 always seems to have a lot of soot in the exhaust yet the dyno man reckons the mixture is correct all the way through.  I try to drive it hard but my 140 mile commute is done largely on motorways at maybe 90 on cruise.  I thrash it a bit at each end.  After a track day they looked a bit cleaner (I could see some bits in the back box that were clean, but the pipes themselves were sooty still)

I see there's another evo in the car park today which looks non-standard in every way with some sort of aftermarket upswept tailpipes and they are clean as a whistle.

Any ideas?

Andy

the outside of mine is sooty?

"If the car is running right and fuel economy is within acceptable limits I wouldn't worry about it."

Ahhh the voice of reason.  Thanks!

But still interesting though.

Andy