E85 Flex Fuel - 2019 AT4

[TXGREEK]

Yes,  a 50/50 mix no issues.  Been running it that way for over 3 years now. 

 

Last night I filled 6 gallons of E85 then filled up with super. From what I’ve been reading about how clean engines are using E85, I’m hoping it’ll keep things clean in there.

 

 

Sent from Above

 

[Black02Silverado]

13 minutes ago, TXGREEK said:

 

Last night I filled 6 gallons of E85 then filled up with super. From what I’ve been reading about how clean engines are using E85, I’m hoping it’ll keep things clean in there.

 

 

Sent from Above

 

Burns cleaner and cooler and has a higher octane.  Whats not to like?

[TXGREEK]

Burns cleaner and cooler and has a higher octane.  Whats not to like?

 

I’m all for cleaner and cooler burning! I actually smelled a difference just by adding only 6 gallons, doesn’t smell like burnt insecticide lol

 

 

Sent from Above

 

[newdude]

17 hours ago, Taz56 said:

I am glad I can come to this community and ask questions but so pissed off the damn dealership could not tell me. I spoke to them and they said "We will find out for you". They never called me back, and yes I rang them up a second time.

 

Anyways, my 2014 GMC Sierra All-Terrain - 5.3L took E85 Flex Fuel. Any car or truck with a yellow gas cap will take it.

My new 2019 GMC Sierra AT4 - 6.2L has no cap and I can't find written anywhere if I can use the E85 Flex Fuel in it or not.

 

Anyone know?

 

 

When the cap-less fuel fill came for 2017, the only identifier is a transparent window decal on the driver's front window, right corner with grayish/white writing on it that says "E85 Flex Fuel".  No sticker, no E85, unless someone scraped it off.  In which case, you have to check the RPO codes for FHO (no E85) or FHS (E85). 

 

For 2019 T1 trucks, the only engine available with E85 capability is the L82 5.3 V8 found in WT/Custom/Custom Trail Boss on Chevy and Sierra base trim for GMC.  L82 is the carryover L83 engine from 2014-2018 with a couple small changes.  It is not standard on those trims either, its a $100 option and would show on the window sticker.  That is the only engine 2019+ T1 that is E85 compatible. 

Edited October 25, 2019 by newdude

[Donstar]

The V6 in the WT is probably FF compatible.  I know there must be more to a vehicle designated as FF than a sticker.   I'd be inclined to want to know the difference before running E85 in a non-flex fuel vehicle.  

[KARNUT]

In the recent past the only difference was a sensor taking advantage of octane boost. I can’t imagine GM would completely change the fuel lines and such making it harmful to use E-85.


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[L86 All Terrain]

E85 ethanol is harsh on seals and fuel lines. Many o ring seals and fuel lines for E85 engines are made with a different compound of rubber that is more resistant to ethanol. Concentrations as high at 85% (E85) can damage fuel lines and seals if the engine is not designed for it. Not saying they didn't use butyl rubber in the L86/87 trucks, but they also don't have the sensor that detects ethanol percentages. 

 

They're a fairly high compression engine, 11.5:1 so they recommend premium fuel (91+) so the engine doesn't have to retard time to prevent pre-detonation or "pinging". You should never use blended fuel in older small engines, or any 2 stroke engine. They need premium fuel. I like to mix 100 low lead airplane gas with premium for my high performance 2 stroke engines because even 91 sucks these days.  

[jumpinjoe]

6 hours ago, Black02Silverado said:

Burns cleaner and cooler and has a higher octane.  Whats not to like?

It's hygroscopic (attracts water), it's very corrosive to most materials, and provides a substantial loss in MPG compared to non-contaminated gasoline. Other than that, it's great stuff. ..............

 

Regards,

jumpinjoe

[jumpinjoe]

7 hours ago, Cpl_Punishment said:

Sorry, that's on his ski boat, not an air boat. I can't remember for sure what he used to run on his remote control boats and air boats but I can ask him. 

OK, now that makes a little more sense. You had me going for a moment that there was something out there I was missing for my air boat.  Matter of fact I'm a staunch fan of 2 strokes for outboards. Generally speaking, HP/weight is usually much better on the 2 stroke. And I just love to hear that high winding hum.

 

I recently passed on a great buy of an outboard boat (left over 2018) simply because it had a 4 stroke outboard on it. I even offered to pay to have the motors switched out ...... take the 4 stroke off and install an equivalent 2 stroke. Dealer wouldn't go for it. His tech says the 4 strokes are harder to sell. LOL! Guess that about says it all.

 

Obviously some folks will like the 4 stroke better and that's perfectly fine ..... You know, different 'strokes' for different folks. I never talk down another man's preference unless he asks me for it. That's his decision and I'll respect that.

 

Regards,

jumpinjoe

[redwngr]

On 10/24/2019 at 3:46 PM, Taz56 said:

I am glad I can come to this community and ask questions but so pissed off the damn dealership could not tell me. I spoke to them and they said "We will find out for you". They never called me back, and yes I rang them up a second time.

 

Anyways, my 2014 GMC Sierra All-Terrain - 5.3L took E85 Flex Fuel. Any car or truck with a yellow gas cap will take it.

My new 2019 GMC Sierra AT4 - 6.2L has no cap and I can't find written anywhere if I can use the E85 Flex Fuel in it or not.

 

Anyone know?

 

 

On 10/24/2019 at 4:17 PM, MX86 said:

The current DFM 5.3l and 6.2l are NOT E85 compatible at this time


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23 hours ago, BlancoSilverado said:

I believe they are up to E15 compatible but i know for sure that the L84 is not E85 compatible 

 

23 hours ago, Black02Silverado said:

The 2019's for the 5.3 and 6.2 are not FF.  Makes me mad that they didn't offer it.  I still run a 50/50 mix of E85 and Premium in mine.  Same goes for my 2002 Silverado.  It isn't flex fuel but I do the same, 50/50 mix.  Love the way they run with it since it boost the octane up nicely.  Not to mention I like the exhaust smell.

 

So there are 2 versions of the 5.3L engines for 2019 (and also for 2020)

L82  which is AFM and L84 which is DFM.

Neither is flexfuel ---

 

BUT as an option on the L82 (which is only available on the base trim level) it can be added. 

 

FHS         E85 FlexFuel capable of running on unleaded or up to 85% ethanol
1 - Requires (L82) 5.3L EcoTec3 V8 engine. Not available with (ZW9) pickup bed delete. 

 

 

Back in 14/15 time frame the E85 capable trucks came with an alcohol sensor and the computer would change the fuelling, depending on the % alcohol detected.

GM published higher horsepower ratings for the 5.3 when running on E85 on an engine with the sensor and variable fuelling tables.

 

EDIT to add -- back to original question -- no E85 capability on an AT4.

 

 

 

 

 

Edited October 25, 2019 by redwngr

[Doolin-Dalton]

On 10/24/2019 at 3:46 PM, Taz56 said:

I am glad I can come to this community and ask questions but so pissed off the damn dealership could not tell me. I spoke to them and they said "We will find out for you". They never called me back, and yes I rang them up a second time.

 

Anyways, my 2014 GMC Sierra All-Terrain - 5.3L took E85 Flex Fuel. Any car or truck with a yellow gas cap will take it.

My new 2019 GMC Sierra AT4 - 6.2L has no cap and I can't find written anywhere if I can use the E85 Flex Fuel in it or not.

 

Anyone know?

 

They do not, only the 2019-2020  "Fleet" vehicles come with the yellow caps now - BUT - see my other post on using e85 in my 2019 Trail Boss 5.3L V8 as well as several other folks that commented that they are using it.  Below is my .02 and observation. I'm not a mechanic, so this is not advice, it's merely my observation.

 

1) I looked at the fuel lines under my truck, and they are labeled for e85.  Forgive me, I forget the code, but they are marked something like EVOH which is the e85 spec

2) I have a JET Stage II Performance Module installed on my truck, which among other things (i) advances the timing

3) Been mixing e85 and 93 Octane Gasoline, usually 50-50 (12 gallons each) sometimes I take it up a notch to 60-40 ratio or 14gal e85 to 10gal 93 octane gasoline

4) Some people will say this is stupid, that the ECM and the engine cannot handle it, the truck won't know what to do.  I think this is completely false.

5) I've noticed that when I run the 50-50 e85 to gasoline mix, I get 14-15mpg, compared to the 22mpg I normally get when 100% gasoline, i.e. cruising on I-95 interstate speeds.

6) Been doing it for several months, 2000 miles, not a single hiccup.  Tons of power, you can hear/feel a difference, 5.3L on e85 is "WOKE"

7) How is it possible, that the truck would consume 14-15mpg using the e85, and 22mpg on Gasloine?  I believe the ECM is calibrating this, there must be a sensor that is capturing the e85 content.  Even though it's not advertised by GM, I think the capabilities are in the truck already.  I'm not willing to go 100% e85 yet, but if I do, will share it later.

8)Coincidentally, my 2016 Silverado 2500 was Yellow Capped for e85.  When I used e85, I'd get about 14mpg.  When I used 93 octane gasoline, I could get into the 20s taking it easy at 55mph.  

9) e85 will provide a 10-15% increase in HP in your truck.  It is also known that is has a reduction of about 30% in fuel economy (it has tons more octane which generates the power, but less energy in the fuel itself, so the motor will consume 30% more of it litre per litre compared to gasoline)  The price is $1.70 gallon around here, so well worth it.  

just my .02  

 

 

Edited October 25, 2019 by Doolin-Dalton

[Cowpie]

The only 6.2 I know of that is still Flex Fuel is the Ford 6.2 in their pickups. 

 

I really like E85.  I use it exclusively in my 2015 2500 6.0 and the wife's 2017 Equinox.  The latter has 11.2:1 compression, and while it will take regular, it does far better on higher octane fuels.  And E85 is 100 octane and $2 a gallon compared to $2.94 for premium in my area.  The Nox has been fed E85 almost exclusively since we bought it.  

 

My 2500 has been on E85 exclusively for the last 3 years.   Runs great on the stuff and there is almost no tail pipe deposits.  The high compression DI GM 6.2 L86 would really benefit from E85.  It needs higher octane to bring out the most in the engine.  The new 6.6L L8T gasser in the 2020 2500/3500 would be a great candidate for E85 tuning.

 

It boggles the mind that GM was so on board with flex fuel in past years and now is dropping the capablity from many of its vehicles.  I understand others not wanting to use the stuff, but those of us who do are being left out.  it really is cheap for an OEM to make a regular production vehicle flex fuel capable.    Guess we will have to turn to 3rd party tuners to get tunes that allow for use of E85.  The fuel systems on all new production vehicles are more than up to the task of dealing with E85.

 

For those motivated to do so, DynoTune in South Dakota specializes in E85 tuning using Diablo Tune and EFI Live.  They have a very good reputation.  If I move up to a pickup that doesn't have E85 capability, I will give them a call.

 

http://dynotuneusa.com/Welcome.html

Edited October 26, 2019 by Cowpie

[CamGTP]

There is no sensor and if the truck is not E85 equipped, even the virtual sensor is set to disable. That is done even on the K2XX trucks.

 

GM has also been setting stoich to E10 ratings of 14.1 since 2014ish. The way the computer can still try to achieve stoich is through fuel trims. It can sense that something is different with the E85 mix that some people run but it can't tell the actual alcohol content. Fuel mileage is still going to be less because of the fact that the computer is smart enough to use the fuel trims to make it run good.

 

Saying 10-15% increase in power is a stretch. I'd have to go back the wiki page for exact numbers but I believe GM rated the GEN V 5.3 engine at 355hp and 383hp on E85. That is an increase of only 7-8% and that is on real E85. The torque increase is the roughly the same at 6-7%.

[Thomcat]

On 10/25/2019 at 9:54 AM, Donstar said:

The V6 in the WT is probably FF compatible.  I know there must be more to a vehicle designated as FF than a sticker.   I'd be inclined to want to know the difference before running E85 in a non-flex fuel vehicle.  

Easiest way to confirm is send an Email to customer service..  [email protected]   ..requesting RPO code for your vehicle, among other things it will show what engine was installed and fuel requirements, e.g. mine was L84 V8 DFM  E15 capable.

[Donstar]

31 minutes ago, Thomcat said:

Easiest way to confirm is send an Email to customer service..  [email protected]   ..requesting RPO code for your vehicle, among other things it will show what engine was installed and fuel requirements, e.g. mine was L84 V8 DFM  E15 capable.

Yes, I believe all of the Ecotec 4.3 V6's come FF compatible. I would not run E85 on a non FF designated engine.  I am sure there are significant differences to accommodate  E85 and using unapproved fuel will most certainly void powertrain warranties.