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Discussion Starter #1 (Edited)
Almost everyone these days is aware of the bad rep that e85 has gotten from internet horror stories and 2nd hand opinions. Over the 3 years that I ran my car on ethanol, I had no issues caused by the fuel. I had assumed this had been due to AZ’s lower humidity or possibly higher quality e85.

After moving and living in Michigan for the last 8 months, my car began to sputter and perform poorly. After investigating, I found the issue was due to a very sticky, tar-like residue that had accumulated on and in my fuel system. This tar (pictured below)/ would not breakdown with brake clean or other common solvents. I began searching for and trying other options.

The first fuel I tried that broke down the residue was pump 100oct unleaded Sonoco 260GT (CAM2). The tar dissolved shortly after pouring the race gas, and I posted pictures below showing the results. From what I read about the fuel, there doesn't seem to be any special additive in the race gas to cause this, which leads me to believe that regular gas (87-93oct) should have the same effect. However, I haven't tested this concept for myself yet.

I do not know the chemical reasoning behind why gasoline breaks down the tar when brake parts cleaner and other solvents do not, but what I can confirm is that it works, and wanted to share this info with everyone. Maybe some other members that know more about each fuels chemical properties can chime in and give a more in depth explanation.


Hope this helps people in the future if/when this issue is encountered!



TLDR:
- Ran E85 for 3 years in AZ with no trace of fuel problems/tar or buildup
- Moved to Michigan for work and tar/residue accumulated in fuel system restricting fuel flow in pump, filter, injectors, etc.
- Searched the web for verified solutions and found none.
- Experimented with different methods to remove the residue.
- 100 octane unleaded race gas was the first fuel I tested that rapidly dissolved the residue
- Due to this confirmation, I would believe that regular gasoline should have the same results but I haven’t verified this yet.
- Before and After pictures posted below


BEFORE:



AFTER:

 

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This is good information. Being that I have a flex fuel setup I purposely run 91 octane pump gas through the car every 3rd or 4th fill up. Seems to do the trick as I don't have any buildup on the swirl pot. After running straight e85 for a couple of consecutive years I was seeing tar buildup on the intake ports of the head as well. Since then I figured it wouldn't hurt to run some pump gas through at regular intervals.
 

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I've found that running a filter on your gas jug before putting e85 helps a ton with the crud buildup. The fuel itself just tends to be a bit dirty out of the pump.
 

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WOW, that's crazy. Thanks for posting.

Steve
 

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I believe some of the reason that this has come to light could possibly be related to reused tanks at some stations. I know of a few stations that converted diesel tanks to Ethanol tanks.

I purposely looks for new stations with new tanks and avoid such places if I can. I also tend to run E30-E50 most of time unless I know I am explicitly looking for all-in results.

DP
 

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Boost Junkie
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I believe some of the reason that this has come to light could possibly be related to reused tanks at some stations. I know of a few stations that converted diesel tanks to Ethanol tanks.

I purposely looks for new stations with new tanks and avoid such places if I can. I also tend to run E30-E50 most of time unless I know I am explicitly looking for all-in results.

DP
I agree. Luckily the Thornton's gas stations around here actually installed new dedicated E85 tanks when they started selling it. The other ones that sell it are Meijers and they also are new. I've never seen this type of build up in my personal car, but it is good that people share their experiences.

Steve
 

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I believe some of the reason that this has come to light could possibly be related to reused tanks at some stations. I know of a few stations that converted diesel tanks to Ethanol tanks.

I purposely looks for new stations with new tanks and avoid such places if I can. I also tend to run E30-E50 most of time unless I know I am explicitly looking for all-in results.

DP
I agree. Luckily the Thornton's gas stations around here actually installed new dedicated E85 tanks when they started selling it. The other ones that sell it are Meijers and they also are new. I've never seen this type of build up in my personal car, but it is good that people share their experiences.

Steve

Agreed. In Southern California I have been running E85 for5+ years straight and my fuel system looks as good as new. I even pulled the injectors out and had them flow tested and they were the exact same as when I bought them.
 
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