Ethanol is "Gods racing gas"
In an E47 tune, just the Ethanol content itself is good for 30hp & 60'lb of torque in our LNF engine.

It really is just that easy.
I've run E47 & E24 in my buggy since new, 12 years now
And before that E60 in my 1998 LS1 Z28 for 3 years.

I have never had a problem with Ethanol content .
It has always been 85% or close to it ,non winter.
In the winter it has always been at least 70%.​​​

I used to use a 'test' tube to check Ethanol content, & never saw a problem.
If the Ethanol content is off, our ECM will adjust, no problem.
It has never been a PITA,
Everyone that is looking for more power uses Ethanol if available.

I have never experienced 'hard' starting.
This morning it was in the 30s & startup was perfect as always.
Idle under 1,000 rpm as I have always disabled that crazy high rpm stupid factory startup crap.

So, E47 is a 1 to 1 ratio of one gallon of E85 + one gallon of 91/93 gas.
85+10 =95 divided by 2 = 47.5, which we just call an E47 blend.

So, E24 is a 1 to 4 ratio of one gallon of E85 + 4 gallons of 91/93 gas.
85+10+10+10+10 = 125 divided by 5 = 25, which we call an E24 blend.

If the winter blend is E70 it becomes an E22 blend & is zero problem for the ECM to adjust, when tuned for an E24 blend.

Good read:
https://dspace.mit.edu/bitstream/han...953430-MIT.pdf

Another good read:
https://dspace.mit.edu/handle/1721.1/69496

 

Interesting. Thanks for the insights. And in my first comment, I shoulda said thanks for the files! And asked, what are the ethanol compatibility issues? My 2010 SS I’ve heard from one source has ethanol-safe injector seals, and from another says no, larger injectors than prior years.

What city are you in? Out here we need to be prepared to start up at -20F. I just called the only station in the area that sells E85 (that I know of) to ask about ethanol % and the manager said “It varies so much we never know what it is.” Now I’m afraid my OCD will compel me to call corporate and try to extract more info, and maybe go get a sample at that station (easy because I have a flex-fuel 2.2 HHR.)

My point about hard starting wasn’t about your car, direct injected and optimized for a high ethanol blend. For all I know it would start fine with 100 ethanol at 20 below. But if even a few customers with the many varied flex-fuel cars have trouble, that would be an unacceptable situation for a fuel retailer.

 

Will the ecm adjust to plain premium if E47 or E20 isn't available.

 

Yes it will, but it will ONLY adjust the fuel mixture.
The 'range' of the fuel trim is +30 to -30
BUT if you have the 'proper' timing, meaning 'tuned' for E20 or E47, your timing WILL be too aggressive for premium E10.
So, the 'knock' sensors will do their very best to manage the timing, but it's best to drive lightly until you get the proper E20 or E47 mixture back again.


It's best to have a laptop with you so you can use the proper tune for the mixture your changing to.
It only takes less than 5 minutes to change your tune.
If you don't have a laptop with HPTuner to change tunes, stick to an E20 tune.
Then switching between E10 gasoline & a E20 mixture is less of an issue.

When I arrive at the track I load my 'race' tune.
Before I leave the track & I reload my 'street' tune.

Finding Ethanol in my area has never been a problem for the last 15 years.
Once you go to an Ethanol mixture, you will never go back to gasoline.
I would never go to an Ethanol mixture if I thought finding Ethanol would be a problem, if I didn't have a laptop with HPTuner.

 

Thank you for sharing all of your efforts.

I was hoping to find something like a stealth tune so I could switch between the GM performance tune and an E47 tune.
I guess I'll buy an HPtuner and install your setup.

 

I have a 2008 auto/tranny HHR SS, but I don't think my SS uses E85 FUEL, just PREMIUM GASOLINE. Would your TUNE FILES work on my 08 SS?...