White Audi A8L: Black exhaust tip and carbon buildup around lower bumper
#11
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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.
#12
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.
#13
AudiWorld Member
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.
My personal experience with Ethanol and general information out there is what I am basing the above on.
#15
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... .
#16
#17
AudiWorld Super User
#19
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.
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.
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