[CU2] Excessive oil consumption

[Fredoops]

So a quick question - I was just in the garage and checked inside one of the exhausts. It is certainly sooty (my finger was black from running my finger along the inside). Is this normal? Should it be essentially clean?

Most cars I've cared to inspect this way over the years have been dirty, but they were also old - not a modern car with all the emission restrictions they now have.

Running rich perhaps?

^
I disagree. I've moved from 10W-40 semi to 10W-50 full-synth and I'm retaining about 1L extra oil every 5,000KMs.

Might that have something to do with the fact you switched from semi to full synth?