Soot on exhaust pipes

[911 575F1]

My 997.2 has just completed 11k, the exhaust tips are noticeably cleaner between tank fill up's than when it was new. I used to have to clean the black build up weekly because they looked like they'd been black powder coated. They now still get a discolouration but it's much thinner and even after 400km's they show some of the clean steel surface. I use the car daily with many short runs up to 5km and weekly long runs that may be several hundred KM's. I rev the car hard across the board so it's often at red line and I notice the soot is less than when it's driven more conservatively. Overall the oil consumption is slowing down still high in my opinion (1 ltr / 1500/2000km), but improving. Has anyone experienced the soot levels on the exhaust tips changing over time? I read a lot on the USA forums about this issue and linking it to basic DFI engine behaviour.

[GC9911]

Yes i have the same soot but it's only on the inside of the tips (if you get my drift), so far i have about 4,500klms on my C4. oil use is down too, only used 400ml in the last 1000klms.