What...Wait..E85? Seriously
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Instructor
Joined: Jun 2010
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From: Shell Knob, MO
What...Wait..E85? Seriously
Ok...is it true? Is E85 Gasoline acceptable to use in a 2021 C8? Does the mileage and performance drop off? I thought I had to run no less than 91 Octane. Please..someone fill me in.
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From: Granada Hills CA
Pro
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Octane and ethanol code are unrelated.
91 Octane
E15 or less
Using E85 will damage fuel system.
As noted in the manual:
"Do not use any fuel labeled E85 or FlexFuel.
Do not use gasoline with ethanol levels greater than 15% by volume."
91 Octane
E15 or less
Using E85 will damage fuel system.
As noted in the manual:
"Do not use any fuel labeled E85 or FlexFuel.
Do not use gasoline with ethanol levels greater than 15% by volume."
Melting Slicks
Joined: Feb 2023
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From: Northern Virginia
2023 C8 of the Year Finalist - Unmodified
Assuming you can get real E85 (good luck at a pump).... you can run up to 5-6 gallons of it with 93 and not have any issues.
Go to this thread to get better educated on this. https://www.corvetteforum.com/forums...tock-tune.html
DO NOT run pure E85 in your car....unless you have the sensors and are tuned for it.
Go to this thread to get better educated on this. https://www.corvetteforum.com/forums...tock-tune.html
DO NOT run pure E85 in your car....unless you have the sensors and are tuned for it.
Pro
Joined: Oct 2013
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Being able to run engine on greater than E15 is not the same as not damaging the fuel system.
The higher alcohol content could damage elastomers and plastic in the fuel system as well as the fuel pump.
Its your car so do what you want and be prepared for expensive repair issues not covered by the GM warranty.
The higher alcohol content could damage elastomers and plastic in the fuel system as well as the fuel pump.
Its your car so do what you want and be prepared for expensive repair issues not covered by the GM warranty.
Pro
Joined: Oct 2013
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You can find kits up to $5000 to replace sensors and affected parts. I just read one added 35 rwhp. Your fuel economy however will drop over 20%. Also any such mods will void your warranty.
What are you trying to accomplish?
What are you trying to accomplish?
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From: Ashland, OH
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Melting Slicks
Joined: Feb 2023
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From: Northern Virginia
2023 C8 of the Year Finalist - Unmodified
I am not telling you what to put (or not) into your own car. I am telling you that the other thread I linked above has a lot of good information in it about using E85 to get to E30 in these cars.
Why Closed-Loop Systems Can Handle E30
1. Adaptive Fuel Management:
Links to studies:Most modern vehicles can run E30 effectively, the legal and warranty implications are the key reasons automakers stick to E10/E15 recommendations. If you’re willing to accept these risks, the technology in your car is more than capable.
Why Closed-Loop Systems Can Handle E30
1. Adaptive Fuel Management:
- Closed-loop systems use oxygen sensors and real-time feedback to adjust air-fuel mixtures. This allows them to compensate for the higher oxygen content in E30, which can result in a leaner burn if unadjusted.
- E30 has a higher octane rating (around 94-96), which allows the engine to handle advanced timing and increased compression without knocking. This can improve performance and efficiency in engines designed to take advantage of higher-octane fuel.
- Studies, such as those from the National Renewable Energy Laboratory (NREL) and Department of Energy (DOE), suggest that many post-2001 vehicles (approved for E15) can tolerate E30. Testing often shows no significant wear or damage, with some vehicles even achieving cleaner emissions.
Links to studies:Most modern vehicles can run E30 effectively, the legal and warranty implications are the key reasons automakers stick to E10/E15 recommendations. If you’re willing to accept these risks, the technology in your car is more than capable.
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Joined: May 2024
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From: Ohio
Wow...so you'll risk damaging your car and voiding the warranty to feel like you're saving a little in gas. For what it's worth, at least around here the last time I checked, if you do the math considering the lower fuel economy you get with E85 even with a lower per gallon cost, it actually costs more per mile than 91 octane E10.
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^ Good decision IMO.
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From: Armonk, NY
Being able to run engine on greater than E15 is not the same as not damaging the fuel system.
The higher alcohol content could damage elastomers and plastic in the fuel system as well as the fuel pump.
Its your car so do what you want and be prepared for expensive repair issues not covered by the GM warranty.
The higher alcohol content could damage elastomers and plastic in the fuel system as well as the fuel pump.
Its your car so do what you want and be prepared for expensive repair issues not covered by the GM warranty.
Melting Slicks
Joined: Oct 2008
Posts: 2,066
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From: Pasadena Texas
I just had it done by Peitz Performance in the Houston area who is the only authorized vendor in Texas, south of Dallas. Full tune (including unlocking the ECM) just under $4,900. This included the E85 hardware from DSX the Global B flex fuel kit, that picked up 35 RWHP. https://dsxtuning.com/pages/global-b
I couldn't find any youtube videos of a bone stock car going to E85 only as most had some sort of mods. Going from a bone stock 2021 Z51 to a tuned car earned 1 RWHP, which is so small a lesser or greater DA could cause that difference.
The actual tune and dyno is about a day long process, however sending the ECM to HP Tuners, getting it unlocked, then sending it back is up to HP Tuners. During this time they need to install a DSX global flex fuel kit.
I couldn't find any youtube videos of a bone stock car going to E85 only as most had some sort of mods. Going from a bone stock 2021 Z51 to a tuned car earned 1 RWHP, which is so small a lesser or greater DA could cause that difference.
The actual tune and dyno is about a day long process, however sending the ECM to HP Tuners, getting it unlocked, then sending it back is up to HP Tuners. During this time they need to install a DSX global flex fuel kit.
Last edited by OLD_GOAT; Dec 30, 2024 at 10:18 AM.
Melting Slicks
Joined: Feb 2023
Posts: 2,368
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From: Northern Virginia
2023 C8 of the Year Finalist - Unmodified
I just had it done by Peitz Performance in the Houston area who is the only authorized vendor in Texas, south of Dallas. Full tune (including unlocking the ECM) just under $4,900. This included the E85 hardware from DSX the Global B flex fuel kit, that picked up 35 RWHP. https://dsxtuning.com/pages/global-b
I couldn't find any youtube videos of a bone stock car going to E85 only as most had some sort of mods. Going from a bone stock 2021 Z51 to a tuned car earned 1 RWHP, which is so small a lesser or greater DA could cause that difference.
The actual tune and dyno is about a day long process, however sending the ECM to HP Tuners, getting it unlocked, then sending it back is up to HP Tuners. During this time they need to install a DSX global flex fuel kit.
I couldn't find any youtube videos of a bone stock car going to E85 only as most had some sort of mods. Going from a bone stock 2021 Z51 to a tuned car earned 1 RWHP, which is so small a lesser or greater DA could cause that difference.
The actual tune and dyno is about a day long process, however sending the ECM to HP Tuners, getting it unlocked, then sending it back is up to HP Tuners. During this time they need to install a DSX global flex fuel kit.
E85 is AWESOME. It has always irritated me that Chevy does not make their cars run on it....
Even E30 in these cars gives you a little extra umpf with that 96/97 octane. I get people's fear factor bur there is so much data out there to counteract the misinformation that runs around.
Last edited by SMOKN C8; Dec 30, 2024 at 10:28 AM.
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Originally Posted by d16dcoe45
It won't damage anyrthing. Pretty much every car today is equipped with materials to handle ethanol. The furel you use is already E10 and it does fine. As far as running E85, you obviously need a tune for it and often more injector and fuel pump capacity. But nothing physically bad will happen to the fuel system itself by running it.
"However, it is NOT recommended to put E85 fuel in any vehicle other than a flex fuel vehicle. Doing so can ruin the engine and void the manufacturer's warranty."
Melting Slicks
Joined: Oct 2008
Posts: 2,066
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From: Pasadena Texas
That's right. I've modded several different cars since my 2005 GTO, so this isn't my first rodeo at modding.
Last edited by OLD_GOAT; Dec 30, 2024 at 03:35 PM.
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Blending ethanol gas, IMO is to mainly increase the octane number--- and then only if your engine programming can take advantage of it.
This tool is fun to play with: https://www.tunedbyzfgracing.com/ethanol-calculator
This tool is fun to play with: https://www.tunedbyzfgracing.com/ethanol-calculator