E 85
Pro
Joined: Nov 2017
Posts: 713
Likes: 506
For starters, you can't just put it in the tank and boom it will run it.
First, you need a flex fuel sensor. Second, you gotta wait for someone to crack the new ECUs in these cars to then access the files and activate the capability in the ECU for flex fuel.
So until someone cracks the ECU to tune it, you can't really run E85 yet.
That said, its good easily for SAE 25hp in the L83 5.3 from 2014-2018 per GM. These high compression DI engines love it. And its cheap. As low as $2.21/gal, up to $2.59/gal near me compared to $3.35/gal for 93 near me. The downside? Uses it faster. I think its 30% more fuel consumption? About a 3mpg loss.
Last edited by Newdude; May 17, 2021 at 08:47 AM.
Safety Car
Joined: Sep 2015
Posts: 4,785
Likes: 1,417
It's not recommended because you will blow up the engine. Since there is ZERO way to change the ecu tuning or fuel flow, (required to run 85% alcohol), you can't get anywhere close to a correct A/F ratio. Thus,vroom, boom then clunka, clunka, clunka...
Welcome to the forum.3
Maybe someday when GM allows the ECU to be tuned, but until then.. Nope.
Welcome to the forum.3
Maybe someday when GM allows the ECU to be tuned, but until then.. Nope.
Pro
Joined: Nov 2017
Posts: 713
Likes: 506
A bit exaggerated there. It will probably run a little crappy, but it won't blow up.
Le Mans Master
Joined: Jul 2000
Posts: 6,559
Likes: 4,502
From: North Dallas 40 TX
Are you willing to back your confidence that it "won't blow up" with monetary assistance if it does?
Pro
Joined: Nov 2017
Posts: 713
Likes: 506
Given it takes 30% more volume and the injectors may not be able to flow 30% more that the engine currently requires, it could go so lean as to melt a hole in your piston, so maybe not a literal explosion with a fireball and mushroom cloud, but significant damage is not out of the question. The engine does run run open loop most of the time, and has a wideband O2 sensors, it might be able to accommodate E85 in some low load circumstances without significant engine damage but I wouldn't do it on purpose. But under full load, "let's see how much more power it will make" circumstances, significant damage could result and it would not be covered under warranty.
Are you willing to back your confidence that it "won't blow up" with monetary assistance if it does?
Are you willing to back your confidence that it "won't blow up" with monetary assistance if it does?
If someone accidentally put a full tank of 87 or E85 in a C8, the 87 octane would damage it wayyy faster than E85. A 2014-2018 factory 5.3 flex fuel and non flex fuel use the same fuel pump and injectors. Difference between them? ECM tuning. Flex fuel has the sensor and the E85 tables active.
Le Mans Master
Joined: Jul 2000
Posts: 6,559
Likes: 4,502
From: North Dallas 40 TX
If someone accidentally put a full tank of 87 or E85 in a C8, the 87 octane would damage it wayyy faster than E85. A 2014-2018 factory 5.3 flex fuel and non flex fuel use the same fuel pump and injectors. Difference between them? ECM tuning. Flex fuel has the sensor and the E85 tables active.
6th Gear
Joined: Oct 2023
Posts: 6
Likes: 6
New 2023 c8
I just filled up 12 gallons of e85 . It ran just fine . Nothing happened and the car is stock.
this got me worried. Glad I tried
this got me worried. Glad I tried
For starters, you can't just put it in the tank and boom it will run it.
First, you need a flex fuel sensor. Second, you gotta wait for someone to crack the new ECUs in these cars to then access the files and activate the capability in the ECU for flex fuel.
So until someone cracks the ECU to tune it, you can't really run E85 yet.
That said, its good easily for SAE 25hp in the L83 5.3 from 2014-2018 per GM. These high compression DI engines love it. And its cheap. As low as $2.21/gal, up to $2.59/gal near me compared to $3.35/gal for 93 near me. The downside? Uses it faster. I think its 30% more fuel consumption? About a 3mpg loss.
First, you need a flex fuel sensor. Second, you gotta wait for someone to crack the new ECUs in these cars to then access the files and activate the capability in the ECU for flex fuel.
So until someone cracks the ECU to tune it, you can't really run E85 yet.
That said, its good easily for SAE 25hp in the L83 5.3 from 2014-2018 per GM. These high compression DI engines love it. And its cheap. As low as $2.21/gal, up to $2.59/gal near me compared to $3.35/gal for 93 near me. The downside? Uses it faster. I think its 30% more fuel consumption? About a 3mpg loss.
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6th Gear
Joined: Oct 2023
Posts: 6
Likes: 6
I did this and it not blow up the engine
I added 12 gallons of e85 to my stock 2023 c8
it drove fine.
maybe even better than normal.
used all of it .
engine is not blown. I will do it again.
it drove fine.
maybe even better than normal.
used all of it .
engine is not blown. I will do it again.
It's not recommended because you will blow up the engine. Since there is ZERO way to change the ecu tuning or fuel flow, (required to run 85% alcohol), you can't get anywhere close to a correct A/F ratio. Thus,vroom, boom then clunka, clunka, clunka...
Welcome to the forum.3
Maybe someday when GM allows the ECU to be tuned, but until then.. Nope.
Welcome to the forum.3
Maybe someday when GM allows the ECU to be tuned, but until then.. Nope.
Drifting
Joined: Jun 2021
Posts: 1,295
Likes: 755
From: Phoenix, Arizona
How can the dealer tell if the fuel is 87 or E85? How can you or I tell what fuel we might have if we were to have 3 samples? We can tell if it is Nitro.
Administrator
Joined: Apr 2000
Posts: 41,003
Likes: 474
From: Madison, AL
Cruise-In II Veteran
Cruise-In V Veteran
Melting Slicks
Joined: Feb 2023
Posts: 2,368
Likes: 2,495
From: Northern Virginia
2023 C8 of the Year Finalist - Unmodified
6th Gear
Joined: Oct 2023
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Race Director
Joined: Aug 2016
Posts: 12,866
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From: Garden Valley CA
Instructor
Joined: Sep 2022
Posts: 195
Likes: 187
From: Maryland
Just cause it will work, why risk it in your Vette. The majority of C8 owners would never do this to their cars. Take a poll and see.
Melting Slicks
Joined: Feb 2023
Posts: 2,368
Likes: 2,495
From: Northern Virginia
2023 C8 of the Year Finalist - Unmodified
"Please let the customer know, the E85 recipe is variable and changes with the seasons. Sheetz Ethanol content should range 77% +/- 6%. Spring and Fall seasons are the same ratio with Summer being a higher percentage and Winter being a lower percentage of Ethanol in the E85 recipe. Sheetz follows the ASTM (D5798) International Seasonal and Geographical Volatility Class standards as stated in the U.S. Department of Energy for each region we operate in."
My test of the E % was lower than what they said. My testor was like 62.5% E
The only place I am getting true E85 is at the race track or ordering cans of it from Sunoco --- with that I bailed on the idea of trying to blend E30 and just went back to running Top Tier 93/94
Le Mans Master
Joined: Apr 2001
Posts: 5,478
Likes: 718
From: Black Forest CO
Last edited by 7LitreC5; Oct 3, 2023 at 01:37 PM.
Le Mans Master
Joined: Jul 2007
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From: Arkansas
St. Jude Donor '09 thru '17,'22 thru '26
Instructor
Joined: Jan 2017
Posts: 134
Likes: 35
I used to have a 2016 GT350 tuned for flex fuel which ran awesome. I informed the dealer service writer, who also drove a Mustang, and he thought that was cool. What he didn't like was when someone would come in with a drivability issue and not mention they were running high ethanol fuel. He showed me the diagnostic protocol they follow. First on the list was testing the ethanol content.
Last edited by 65sohc; Oct 3, 2023 at 01:33 PM. Reason: misspelling