Baloo588

I found out that the carbon build up can be a bad thing if you see smoke deposit in less than 1 week time after cleaning the car due to rich fuel mixture from gas with ethanol blend. I tend to use mobile because they use less then 10%. I avoid cheap gas at costco, etc due to higher ethanol content of 13-15%. So if there is smoking and black carbon build up around the bumper if the car is not washed for more than 3 weeks then that is fine as long it does not emit black/grey smoke on acceleration during warmer days.

blsching

Thank you. That is very helpful. I will look into my case and let you know if anything of relevance turns up. So far I have left it totally smoked on purpose. I rather like the dark coating, in contrast to the beige. Bob

KickAss

I was researching about buying a new A8 and came across this post. In the interest of good info, just thought I should point out the obvious. Ethanol burns quite a bit more soot-free than petrol/gasoline. The part about more ethanol content = more carbon build-up seems wrong to me.

My personal experience with Ethanol and general information out there is what I am basing the above on.

DavidA

I use WD 40 or a tar remover with a paper towel; do it once a week in winter or any time the car gets washed- weekly in summer.

Free4134

Direct injection engines at partial or low throttle explode a partial load of fuel (a mist of fuel in the middle of the cylinder), which, at the edges, leads to incomplete combustion with soot particles. So, because your engine is so economical, it has a bit of a smoking habit... .

Ravill

It's been my experience that all my white cars have been more prone to showing post combustion material build up.

Its been raining so much recently around here, it's hard to tell if my fire breathing dragon of an S8 is "sooting" more than other white cars I've owned.

jakematic

The soot matches my Oolong Gray almost perfectly

Not normally a fan of white vehicles, but DAMMMMMN your S8 looks nice !

Ravill

Thank you sir!

motegi

I've had my A8L V8 since March and have noted the soot formation around the exhaust tips. Thankfully my car's paint is dark so I don't notice any discoloration of the bumper.

While this is my first Audi, I don't think that the sooting is any worse than other cars that I own or have owned with chromed exhaust tips.

The brake dust on the other hand is MUCH more of a problem with the Audi.