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When to use Flex fuel/E85?

Jsmith86

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cmysstailights Enthusiast

cmysstailights

Posted
Posted
Can we run E85 without modifications to the truck?
-2016 5.3L
No, you will get no benefit from it. Spark and timing have to be adjusted.

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jhbrennan Enthusiast

jhbrennan

Posted
Posted
30 minutes ago, KaptKyle said:

Can we run E85 without modifications to the truck?
-2016 5.3L

Isn't the 2016 5.3l already flex fuel?  If so, you can run E85 with no mods.

cmysstailights Enthusiast

cmysstailights

Posted
Posted
Isn't the 2016 5.3l already flex fuel?  If so, you can run E85 with no mods.
Think there was a year where it is a option to add. No yellow cap cant use

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calgator73 Senior Enthusiast

calgator73

Posted
Posted
Well, the Sheetz stations are all starting to handle e85 around here...so I'm trying it, got have a tank right now that bumped me up to 40% alcohol. I'll hit the station halfway home tonight and that should be near to a full tank of e85. It's right around $2/gallon...

Our pumps are mark "flex fuel", "51 to 83% alcohol".

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This time of year depending on what zone you live in you're probably closer to 51%

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sdeeter19555 Senior Enthusiast

sdeeter19555

Posted
Posted

Just another observation...while my highway/commute mileage didn't take a hard hit (about 2mpg), my city mileage tanked hard. I should get about 120 miles on the first quarter tank, I got 80 miles on flex fuel with mostly city driving.

I've got 60% in the tank right now...

Steve
2012 2500hd 6.0l

Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted

E-85 tunes. This caught my interest when I first heard it. Especially tunes for it. Wow! Access to high octane fuel in a motor with major squeeze could be exciting. GM reports some pretty healthy gains in torque and by extension horsepower.  

The like always the ‘truth’ will rare its head and things unravel. Fast!

According to SUNOCO their E-85R race fuel has an octane rating of 99 (R+M)/2 and is truly 85% Ethanol and 15% high grade race fuel.

Using the E-85 blend calculator at Wallace Racing E-85 with the minimum alcohol content of 50% yields an octane of 93 (R+M)/2 and by default a high of said 99 (R+M)/2 IF race fuel were used and content certified to be 85%.  I trust SUNOCO Racing more than the pump sticker.

Where am I going with this you ask. You didn’t but I’ll editorialize anyway.

For GM to have a dyno sheet they needed to verify the fuels composition meaning they used a fuel such as SUNOCO E-85R. Which means that the usual statement, “Results may vary” couldn’t find a broader application that in this arena.  

From SONOCO Fuels I quote:

In the United States, pump gas is sold based on AKI and it is this value that we typically use to represent a fuel's octane rating. The square yellow octane stickers you see on gasoline dispensers indicate the (R+M)/2 octane rating. BOVs for methanol and ethanol typically overstate octane.

Noooo…really? Would a marketer do that to the public? Sarcasm is appropriate here. As pump E-85 isn’t blended with high grade race fuel and is not often over 50/55% a strong case can be made that there isn’t any more octane available using pump E-85 than there is with gasohol 93 (R+M)/2.

My factory tune yields knock spark retard at 90 (R+M)/2 and it disappears with 93 (R+M)/2 fuel. Meaning my tune is already happy as hogs at feeding time in the 91-92 range. So unless I plan on buying certified race E-85R such a tune is like playing with a two headed rattlesnake at worst. At best, I spent several hundred dollars on a tune that yielded a few horsepower maybe in an rpm range I rarely visit. Come to think of it, never visit. :loser:

:lurk:

KARNUT Senior Enthusiast

KARNUT

Posted
Posted

My truck ran much better on E-85. I had a tune only for the transmission and V4 elimination. I did raise the shift points and firmness. I could feel the V4-V8 nonsense. The best part I paid on average 50cents less than regular. When I bought my truck 12-31-13 there’re were a few tuners black bear included ran test. Every ones results were on 87 grade gas there were significant knock retard events and recommended mid grade gas on the 14 and up 5.3s. That made E85 a real bargain. In my case I would have used it for performance alone. On trips I use reg gas it was a pain trying to fine E-85.


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cmysstailights Enthusiast

cmysstailights

Posted
Posted
Just another observation...while my highway/commute mileage didn't take a hard hit (about 2mpg), my city mileage tanked hard. I should get about 120 miles on the first quarter tank, I got 80 miles on flex fuel with mostly city driving.

I've got 60% in the tank right now...

Steve
2012 2500hd 6.0l


Yeah hwy is about a 2mpg drop. City you get clobbered. City for me is red light every 100ft lol. I get 7 to 8mpg city, dont know what it is on 87 or 89. Never used that fuel.

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Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted
44 minutes ago, KARNUT said:

. Every ones results were on 87 grade gas there were significant knock retard events and recommended mid grade gas .........

To what end? See that's the question. To what end?

 

Today for example there is locally an 11% difference between these two grades. There is not an 11% difference in economy. There is no 'useful' measureable power difference within the range of normal street operation. It' doesn't start easier. Doesn't warm up faster. There is no damage to be expected from allowing the computer to do what it is designed to do. Wont make my tea. Wont fee my dog So...to what end? 

 

E-85. There is about a dollar spread between 93 and E-85 locally. IF the E-85 were actually 85% there would be roughly a 30% decline in economy. Wash. But as it is more likely to be 50-60% the drop is lower but still there. The power can not be tapped or reliably tuned for when the content is all over the map. Alcohol is hydroscopic. People are not experiencing the normal 30% drop in economy because....it isn't really E-85 in anything but marketing jargon that is federally accepted as 'okay to lie'. 

 

E85 makes sense IF you race or pull and are using a know reliable source that delivers what it promises. Sunoco E85R i.e.

 

It also makes sense IF it's the only fuel they have and it 3 AM in Podunk USA with 300 miles to the next stop and your sucking wind. 

KARNUT Senior Enthusiast

KARNUT

Posted
Posted
To what end? See that's the question. To what end?
 
Today for example there is locally an 11% difference between these two grades. There is not an 11% difference in economy. There is no 'useful' measureable power difference within the range of normal street operation. It' doesn't start easier. Doesn't warm up faster. There is no damage to be expected from allowing the computer to do what it is designed to do. Wont make my tea. Wont fee my dog So...to what end? 
 
E-85. There is about a dollar spread between 93 and E-85 locally. IF the E-85 were actually 85% there would be roughly a 30% decline in economy. Wash. But as it is more likely to be 50-60% the drop is lower but still there. The power can not be tapped or reliably tuned for when the content is all over the map. Alcohol is hydroscopic. People are not experiencing the normal 30% drop in economy because....it isn't really E-85 in anything but marketing jargon that is federally accepted as 'okay to lie'. 
 
E85 makes sense IF you race or pull and are using a know reliable source that delivers what it promises. Sunoco E85R i.e.
 
It also makes sense IF it's the only fuel they have and it 3 AM in Podunk USA with 300 miles to the next stop and your sucking wind. 
There has been post in the performance section of significant improvements in 1/4 mile times with E-85. There’s been post with a E-85 tune increasing HP by 50 plus HP. Some people it makes lots of difference knowing there’re not pulling timing cause of KR.



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calgator73 Senior Enthusiast

calgator73

Posted
Posted
To what end? See that's the question. To what end?
 
Today for example there is locally an 11% difference between these two grades. There is not an 11% difference in economy. There is no 'useful' measureable power difference within the range of normal street operation. It' doesn't start easier. Doesn't warm up faster. There is no damage to be expected from allowing the computer to do what it is designed to do. Wont make my tea. Wont fee my dog So...to what end? 
 
E-85. There is about a dollar spread between 93 and E-85 locally. IF the E-85 were actually 85% there would be roughly a 30% decline in economy. Wash. But as it is more likely to be 50-60% the drop is lower but still there. The power can not be tapped or reliably tuned for when the content is all over the map. Alcohol is hydroscopic. People are not experiencing the normal 30% drop in economy because....it isn't really E-85 in anything but marketing jargon that is federally accepted as 'okay to lie'. 
 
E85 makes sense IF you race or pull and are using a know reliable source that delivers what it promises. Sunoco E85R i.e.
 
It also makes sense IF it's the only fuel they have and it 3 AM in Podunk USA with 300 miles to the next stop and your sucking wind. 
Dunno.... the factory e85 tune includes an alcohol sensor to sense the variations you mentioned and for the year or so I had my 14 max tow.... it was fantastic. Night and day difference.

After seeing the Lingenfelter Dyno results and driving with both on occasion I largely agree with you regarding 87 and 89 octane.

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