Is flex fuel also E85?

Brent Davis · Jan 23, 2017

There's a local sheetz gas station that now carries flex fuel that says 51%-83% Ethanol but doesn't say anywhere if it is E85 or not.

Thanks.

Yellow · Jan 23, 2017

We got the same notice in AZ and its E54 usually.

markmurfie · Jan 23, 2017

51% to 83% Ethanol. Its flex fuel because it could be anywhere in between this range. Pumps labeled E85 vary as well. Best to have a flex fuel tune or you need to test and modify the tune for the correct %.

Z_Rocks · Jan 23, 2017

markmurfie said:
51% to 83% Ethanol. Its flex fuel because it could be anywhere in between this range. Pumps labeled E85 vary as well. Best to have a flex fuel tune or you need to test and modify the tune for the correct %.

Not directly related, but I heard that Dodge Demon will have built in tune for 91/93, Race gas and Flex Fuel (which I suppose is the e85).

markmurfie · Jan 23, 2017

A proper flex fuel tune should cover from 0% ethanol to 100% ethanol. Using inferred octane modifiers based on knock sensors just like the inferred ethanol modifier based on fuel trims or just having extra sensors its highly likely the Demon can and will cover all these fuels in one tune and get different power outputs from all of them. The mustang is capable of it and I'm sure newer GM cars are as well.

Jay159866 · Jan 23, 2017

However, I asked Lund for a FF tune with my paxton and he said "Flex doesn't work well on the Blown applications because your MAF is now Blow thru and it is hard for it to learn the correct AFR Mature point. So we keep it non flex."
But to answer your question, you can run E85 on a FF tune. Just give it that few miles to adjust to the fuel.

jvandy50 · Jan 23, 2017

So for the guys running a fuel system and e85 with their FI, are they having to test at the station??

isedawishy · Jan 23, 2017

jvandy50 said:
So for the guys running a fuel system and e85 with their FI, are they having to test at the station??

Yes, I test my local station here and there. It's pretty consistent so I'm not too worried about testing every fill up.

smokinzx14r · Jan 24, 2017

Our E85 pump also reads 51% to 85% .. But also in big letters on the pump reads E85 .. I have not tested it myself but we have a lot of guys that use the same station that do test it and it always comes up E84 to E85 .. I have used 3 tank fills of it and seen plenty of track time with zero problems .. You can get a tester from Jegs or Summit for a few bucks , I have one and it's easy to use .. Mine was tuned using the same fuel from the same station that I use weekly ...

16MustangVet · Jan 24, 2017

you can buy e85 testing kits pretty cheap its just a white stick you dunk in the gas and see what the content is when it changes color is the type ive seen anyways.

i believe zietronics sells flex fuel gauges that has the content sensor in it too so it displays the "strength" or rating of the ethanol.

https://www.maperformance.com/produ...0Ry89ktsRwsqjpYxKzl8wzD-nGhRKVUGlcBoCl-zw_wcB

highly reccomend one if using e85 i for damn sure will have one. i ran into some bad e85 back when i had a cammed gen5 supercharged baby pulley 3800 V6 car on corn.

smokinzx14r · Jan 24, 2017

Jay159866 said:
However, I asked Lund for a FF tune with my paxton and he said "Flex doesn't work well on the Blown applications because your MAF is now Blow thru and it is hard for it to learn the correct AFR Mature point. So we keep it non flex."
But to answer your question, you can run E85 on a FF tune. Just give it that few miles to adjust to the fuel.

Same thing Sai told me ..It can be done but the system takes to long to adjust to the change ..Not good for a FI system .. :headbonk:

16MustangVet · Jan 24, 2017

smokinzx14r said:
Same thing Sai told me ..It can be done but the system takes to long to adjust to the change ..Not good for a FI system .. :headbonk:

Huh? no it doesnt just dont drive like a tard until the afr levels out. anyone going FI should always monitor knock and afr anyways imo and if on e85 need to monitor ethanol content too imo. gauges and some discipline with the gas pedal is good insurance!

I take it youve never had a car that can switch back and forth between pump gas and e85. switching on my old junk box 3800 was worth going down from a 3.4 pulley on the supercharger to a 2.8 and worth about 60 hp according to the dyno. I used to switch from e85 to pump gas right at the stations took me less than 15 min to swap pulley and plug in the e85 tuned pcm.

with a flex fuel tune it would be way easier with out having to switch out the actual pcm. but dropping pullies for e85 is still going to be worth it.

smokinzx14r · Jan 24, 2017

16MustangVet said:
Huh? no it doesnt just dont drive like a tard until the afr levels out. anyone going FI should always monitor knock and afr anyways imo and if on e85 need to monitor ethanol content too imo. gauges and some discipline with the gas pedal is good insurance!

I take it youve never had a car that can switch back and forth between pump gas and e85. switching on my old junk box 3800 was worth going down from a 3.4 pulley on the supercharger to a 2.8 and worth about 60 hp according to the dyno. I used to switch from e85 to pump gas right at the stations took me less than 15 min to swap pulley and plug in the e85 tuned pcm.

with a flex fuel tune it would be way easier with out having to switch out the actual pcm. but dropping pullies for e85 is still going to be worth it.

Huh ?

16MustangVet · Jan 24, 2017

:lol: ill take that as a no youve never had a vehicle that can switch back and forth between e85 and pump gas

its not as complicated as some people like to make it seem.

Brent Davis · Jan 24, 2017

16MustangVet said:
:lol: ill take that as a no youve never had a vehicle that can switch back and forth between e85 and pump gas

its not as complicated as some people like to make it seem.

lol, I'll take it that you don't know who smokinzx14r is then.....

Is flex fuel also E85?

Brent Davis

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Yellow

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markmurfie

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Z_Rocks

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markmurfie

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Jay159866

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jvandy50

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isedawishy

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smokinzx14r

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16MustangVet

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smokinzx14r

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16MustangVet

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smokinzx14r

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16MustangVet

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Brent Davis

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