SFV A4

Tailpipes should be cleaned every time the car is cleaned. If done, there'd be no huge buildup or permanent staining. If you have these problems, you are neglecting the details of your car.

KevinB656

Unless it builds to a point that it materially interferes with the flow of the exhaust, which seems unlikely, the carbon in the exhaust tips would seem to be just an aesthetic issue. The real issue, which is the primary point of this thread, is how to best protect the engine from carbon build up.

minmet

+1

If there is carbon deposited on tailpipes, there must be carbon deposited in engine or some other internal locations which will deteriorate the performance or even causing major problem down the road. That's what we are worried about. I guess it's part of different mentality. Do we care about the longevity or not. People like me bought the car and plan for a longer holding do care. People lease the car for three even less years may not care that much.

gooberman

My Kia Optima has it also. 35k

I never really cared enough to research it but it is also direct injected. Now I know!