Interesting article on ethanol blended gasolines..

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TNVIPER

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I have been doing some reading on ethanol blended fuels...mainly E10 (5-10% ethanol) which is the only fuel sold in most areas in the US....it is considered safe for almost all modern vehicles.......E85 (70-85% ethanol) is only safe for use in flex fuel vehicles....does not include our trucks..

I am mainly concerned about E10 causing lean conditions...the mix gives a slightly false reading that can cause problems for custom tuned vehicles......with E10 my A/F guage reads mid 12s at WOT...little lean for a FI engine.....I found a station about 30 minutes from me that sells 100% gasoline. I ran my tank to almost empty and filled up....my A/F guage now reads high 11s at WOT......any thoughts here?

http://allsafe-fuel.org/TechPaper.pdf





..
 
SHU-DOG said:
I thought our trucks specifically stated NOT to use any kind of ethanolated gasoline???????
Click to expand...

E10 is considered safe for almost all vehicles....the pump should have a sticker on it stating if the gas contains ethanol....E10 will say up to 10%.......E85 will be 70 to 80% with warnings not to use in any vehicle that is not labeled "flex fuel"..
 
I would assume that this would apply to all makes, but as far as GM goes all their vehicles are designed to handle up to 15%.
 
Stingray said:
I would assume that this would apply to all makes, but as far as GM goes all their vehicles are designed to handle up to 15%.
Click to expand...

I have read that about any vehicle can handle up to 20% before sensors are needed to help the PCM adjust.....flex fuel vehicles have sensors in the fuel lines that can determine the ethanol content....but my main concern is what happens with aftermarket tunes....the E10 may be causing A/F readings to be a half point or more off..:dontknow:
 
I'm not an expert by any means but I would say the difference is probably normal. I'm thinking the flashpoint and combustion temperature are the contributing factors.

I know when it comes to E85, it will take 30 to 40 percent more fuel to tune currently.
 
TNVIPER said:
I have been doing some reading on ethanol blended fuels...mainly E10 (5-10% ethanol) which is the only fuel sold in most areas in the US....it is considered safe for almost all modern vehicles.......E85 (70-85% ethanol) is only safe for use in flex fuel vehicles....does not include our trucks..

I am mainly concerned about E10 causing lean conditions...the mix gives a slightly false reading that can cause problems for custom tuned vehicles......with E10 my A/F guage reads mid 12s at WOT...little lean for a FI engine.....I found a station about 30 minutes from me that sells 100% gasoline. I ran my tank to almost empty and filled up....my A/F guage now reads high 11s at WOT......any thoughts here?

http://allsafe-fuel.org/TechPaper.pdf





..
Click to expand...

Are you using cats and O2 sensors?

I have been using nothing but what you are calling E10 (a 10% blend) for over 4 years with cats and O2 sensors. It is also one more reason why I never switched to a 170 thermostat.

Ethanol blends (E10) produce oxygen when they burn and the O2 sensors normally pick up on the extra O2 and will dump in more fuel to compensate.

If you aren't using O2 sensors, the injectors won't be dumping in more fuel when you are burning E10, and that is what your A/F gauge is picking up on (more Oxygen).
One possibility...

If you have to or want to use E10, have your tuner tweak your tune a bit.


Ronnie
 
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It IS actually leaning you out. The stoich A/F for E85 is like 12:1 way more fuel need to reach that point vs. gasoline. Now take a mixed gasoline with up to 10% ethanol and you will notice a lil bit of a lean condition. I could see being a half point off. Shouldn't be detrimental but can be adjusted by adding a lil fuel via injector pulse width or reatarding the timing a hair!:burnout:
 
rottenronnie said:
Are you using cats and O2 sensors?

I have been using nothing but what you are calling E10 (a 10% blend) for over 4 years with cats and O2 sensors. It is also one more reason why I never switched to a 170 thermostat.

Ethanol blends (E10) produce oxygen when they burn and the O2 sensors normally pick up on the extra O2 and will dump in more fuel to compensate.

If you aren't using O2 sensors, the injectors won't be dumping in more fuel when you are burning E10, and that is what your A/F gauge is picking up on (more Oxygen).
One possibility...

If you have to or want to use E10, have your tuner tweak your tune a bit.


Ronnie
Click to expand...

No cats but do have O2 sensors....I was surprised that my A/F dropped into the high 11s with pure gasoline....
 
TNVIPER said:
No cats but do have O2 sensors....I was surprised that my A/F dropped into the high 11s with pure gasoline....
Click to expand...

Even those 10% blends pack more oxygen punch than you'd think...I was surprised when I started using it.
I had my own tune tweaked 1/2 a point to keep things more normal.
 
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rottenronnie said:
Even those 10% blends pack more oxygen punch than you'd think...I was surprised when I started using it.
I had my own tune tweaked 1/2 a point to keep things more normal.
Click to expand...

I am looking at this the right way??....if I have E10 in the tank and my A/F guage reads 12.5 my actual A/F is probably around 13.0?
 
TNVIPER said:
I am looking at this the right way??....if I have E10 in the tank and my A/F guage reads 12.5 my actual A/F is probably around 13.0?
Click to expand...

I would say if your A/F is reading 12.5 (for example), it will be 12.5 with E10 simply because that is what your A/F monitor is reading after the engine controls have tried to make things right, and what is left is heading out the tailpipe anyway...

With straight gasoline it tends to be richer, say 12 or even 11.5 as you noticed when you switched back to straight gas.

I am not running forced induction but I did notice the A/F went leaner with E10, even with the ECU and injectors trying to richen things back up to stoichiometric.
If you have concerns about going lean with E10, your tuner can easily tweak your program to provide even more fuel.

I like E10 (other than the drop in fuel economy) and there is more and more of it coming to the pumps, it seems.

An A/F meter is a valuable tool n.a. or forced induction..
 
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rottenronnie said:
I would say if your A/F is reading 12.5 (for example), it will be 12.5 with E10 simply because that is what your A/F monitor is reading after the engine controls have tried to make things right and what is left is heading out the tailpipe anyway.

With straight gasoline it tends to be richer, say 12 or even 11.5 as you noticed when you switched back to straight gas.

I am not running forced induction but I did notice the A/F went leaner with E10, even with the ECU trying to richen things back up to stoichiometric.
If you have concerns about going lean with E10, your tuner can easily tweak your program to provide even more fuel.

An A/F meter is a valuable tool n.a. or forced induction..
Click to expand...

My main concern with the E10 is that I am already running at the edge of my fuel system capacity to feed 11LBs boost. I sure do not want something that causes me to go over the edge..( ie "fuel pressure").

I had read several articles about leaning with E10. That is why I am trying the pure gasoline which seems to be fattening the A/F about half a point during WOT....I have also noticed the closed loop A/F does not bounce around as much with the pure gas...maybe indicating the ECU does not have to work as hard to maintain stioch..:dontknow:

At any rate I will be getting a dyno tune in about 2 weeks. I might just have the tuner do a 93 octane E10 tune and one for pure gasoline...the E10 tune could be less aggressive on timing with extra fuel...I have the SCT so the room is there..
 
TNVIPER said:
My main concern with the E10 is that I am already running at the edge of my fuel system capacity to feed 11LBs boost. I sure do not want something that causes me to go over the edge..( ie "fuel pressure").

I had read several articles about leaning with E10. That is why I am trying the pure gasoline which seems to be fattening the A/F about half a point during WOT....I have also noticed the closed loop A/F does not bounce around as much with the pure gas...maybe indicating the ECU does not have to work as hard to maintain stioch..:dontknow:

At any rate I will be getting a dyno tune in about 2 weeks. I might just have the tuner do a 93 octane E10 tune and one for pure gasoline...the E10 tune could be less aggressive on timing with extra fuel...I have the SCT so the room is there..
Click to expand...

That sounds like a good plan. That is a great thing about the SCT. I've had DC send a number of tunes, and it is SO easy doing it over the 'net...

I was wondering that myself and it is quite possible that E10 does keep the ECU extra busy. We have large temperature swings where we are and that also adds to the E10 fun, as it requires more heat to burn properly than pure gasoline....:)
 
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