Exhaust tips turning black

[mudblood]

Conoco is on the list currently.


Top Tier Gasoline

Thanks good to know. Good Lord they have added a ton of brands and delaers since I last looked. I used to drag race a lot and I can tell you if you run racing gas your pipes will be pristeen. Course that may not be good for other parts of the engine. I really would have the dealer put it on the computer to check out everything. A ounce of prevention can stop a pound of damage sometimes.

 

[Jimbo]

Yeah, some of them are very questionable in my opinion. I've always been a (in order): Shell, BP, and Mobil guy.


Race gas by me, 100 octane, has always been steady at $6.99/gal for the last 5 years.

 

[MTF]

Is Sunoco sold under a different name or their just not up to par.

I'm asking because quite a few years ago Sunoco stop selling their 96 then the 94 octane and now only sell 93 octane.
I can tell a difference big time between Sunoco and BP 93 octane.
And I do go out of my way to get BP 99.9% of the time, but every once and a while I do get Sunoco because their right around the corner.
So is Mobil but that's even worse.

Any way the black carbon is there no matter what, our trucks run with a 14.2 +/- AFR at idle or cursing which is slightly rich.
It doesn't matter which octane you use, the PCM will always adjust to 14 AFR.

 

[pat247]

It's more than likely from the gas with ethanol, I run pure gas 91 octane and have very little carbon buildup on the tailpipes. Also getting an oil separator will help. I'm an old man and 90% of the time I drive like it, the other 10% I drive like I'm 16.

I had two ecoBoost trucks prior to the Raptor and with the direct injection on those engines the carbon buildup on the tailpipes was horrible. Switching to 91 octane pure gas reduced the amount of carbon buildup quite a bit.