E85 question?
Thread Starter
Safety Car
Joined: Aug 2004
Posts: 4,734
Likes: 232
From: Youngstown Ohio
E85 question?
Wide open question here and i am just starting to search for more information.
So, since I finally have a gas station that will carry E85 and it is considerably less expensive than premium what's it take to convert over?
My car
04 coupe, forged ls6, 8-9 lbs boost with CNC heads, 10.5:1 cr and supporting bolt ons. It's an A&A system Strim running stock fuel system plus a BAP and 60 lb injectors.
Any advice and experience on this would be great, thanks!
Pat
So, since I finally have a gas station that will carry E85 and it is considerably less expensive than premium what's it take to convert over?
My car
04 coupe, forged ls6, 8-9 lbs boost with CNC heads, 10.5:1 cr and supporting bolt ons. It's an A&A system Strim running stock fuel system plus a BAP and 60 lb injectors.
Any advice and experience on this would be great, thanks!
Pat
Thread Starter
Safety Car
Joined: Aug 2004
Posts: 4,734
Likes: 232
From: Youngstown Ohio
Thanks for the reply. Been reading on the topic and have read about all the pros and cons. Not really looking to get extra HP out of the setup just figured it cost less, but less mpg which varies, and can be a safer choice with boost. Most of the reading and opinion is positive but there is some concern about moisture gathering in the fuel. I'm not sure how much of a concern that is though cause opinion is all over the place.
Gonna keep reading,
PC
Gonna keep reading,
PC
Safety Car
Joined: Jan 2008
Posts: 4,797
Likes: 52
From: Boise
It will be safer for sure...you will see a very large hit in MPG. E85 is not fuel for budget conscious people, unless you are comparing to race gas.
You will need multiple fuel pumps and much larger injectors, and a tuner who knows how to tune on E85. A good question to ask is if he adjusts the stoich value, if he says no then you find another tuner.
You will need multiple fuel pumps and much larger injectors, and a tuner who knows how to tune on E85. A good question to ask is if he adjusts the stoich value, if he says no then you find another tuner.
Safety Car
Joined: Jan 2008
Posts: 4,797
Likes: 52
From: Boise
Also for the record....my car went from getting about 290-300 miles per tank, to 180, that's a pretty substantial hit in MPG. Since E85 isn't subsidized anymore it's also barely cheaper than 91/93 most places.
Drifting
Joined: Mar 2011
Posts: 1,412
Likes: 15
From: Richardson TX
Usually E85, cost wise, about evens out with regular gasoline.
The cost difference is usually about the same as the difference in MPG.
You can expect about 2/3rds the mileage with E85 as you do with regular gasoline on a good day, and its usually about 2/3rds the price, depending on market conditions, so its not any cheaper to run it. I almost switched to E85 when I went turbo, but decided not to. Getting ~200 miles to a tank of gas didn't sound like fun, and it basically kills your option to take road trips (and you'd have to fill up every 200 miles on a road trip).
For the inevitable question "Can I have a tune that can run off both E85 and regular gasoline?" The quick answer is no. Theoretically you can do it by running 2 tunes with EFI Live, but you'd have to make sure you had pure E85 or pure gasoline (have to run the tank dry before refilling), and it would be a huge PITA.
TL;DR Don't switch to E85. Its great for a high boost car, but it comes with a lot of downsides.
The cost difference is usually about the same as the difference in MPG.
You can expect about 2/3rds the mileage with E85 as you do with regular gasoline on a good day, and its usually about 2/3rds the price, depending on market conditions, so its not any cheaper to run it. I almost switched to E85 when I went turbo, but decided not to. Getting ~200 miles to a tank of gas didn't sound like fun, and it basically kills your option to take road trips (and you'd have to fill up every 200 miles on a road trip).
For the inevitable question "Can I have a tune that can run off both E85 and regular gasoline?" The quick answer is no. Theoretically you can do it by running 2 tunes with EFI Live, but you'd have to make sure you had pure E85 or pure gasoline (have to run the tank dry before refilling), and it would be a huge PITA.
TL;DR Don't switch to E85. Its great for a high boost car, but it comes with a lot of downsides.
Thread Starter
Safety Car
Joined: Aug 2004
Posts: 4,734
Likes: 232
From: Youngstown Ohio
Premium ~4 bucks a gallon and E85 was $3.17 a couple days ago. First station in the area to carry it and the difference was good and I got to thinking. That's the point at which everything usually starts going bad! 
Too all, Thanks for the replies and that's in line with most of what I had read. All in all I learned a bunch and will probably just pass on this. After all my reading and the info offered here I guess it's obvious why its the first station to carry it in the area, not much demand.
Thanks everyone have a good night,
PC
Too all, Thanks for the replies and that's in line with most of what I had read. All in all I learned a bunch and will probably just pass on this. After all my reading and the info offered here I guess it's obvious why its the first station to carry it in the area, not much demand.
Thanks everyone have a good night,
PC
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Safety Car
Joined: Jan 2008
Posts: 4,797
Likes: 52
From: Boise
Usually E85, cost wise, about evens out with regular gasoline.
The cost difference is usually about the same as the difference in MPG.
You can expect about 2/3rds the mileage with E85 as you do with regular gasoline on a good day, and its usually about 2/3rds the price, depending on market conditions, so its not any cheaper to run it. I almost switched to E85 when I went turbo, but decided not to. Getting ~200 miles to a tank of gas didn't sound like fun, and it basically kills your option to take road trips (and you'd have to fill up every 200 miles on a road trip).
For the inevitable question "Can I have a tune that can run off both E85 and regular gasoline?" The quick answer is no. Theoretically you can do it by running 2 tunes with EFI Live, but you'd have to make sure you had pure E85 or pure gasoline (have to run the tank dry before refilling), and it would be a huge PITA.
TL;DR Don't switch to E85. Its great for a high boost car, but it comes with a lot of downsides.
The cost difference is usually about the same as the difference in MPG.
You can expect about 2/3rds the mileage with E85 as you do with regular gasoline on a good day, and its usually about 2/3rds the price, depending on market conditions, so its not any cheaper to run it. I almost switched to E85 when I went turbo, but decided not to. Getting ~200 miles to a tank of gas didn't sound like fun, and it basically kills your option to take road trips (and you'd have to fill up every 200 miles on a road trip).
For the inevitable question "Can I have a tune that can run off both E85 and regular gasoline?" The quick answer is no. Theoretically you can do it by running 2 tunes with EFI Live, but you'd have to make sure you had pure E85 or pure gasoline (have to run the tank dry before refilling), and it would be a huge PITA.
TL;DR Don't switch to E85. Its great for a high boost car, but it comes with a lot of downsides.
Also the thing about two tunes is completely false, especially when going back to pump gas from E85. 1-2 gallons is not going to make enough of a difference for it to be a worry.
The biggest concern between switching between two tunes is that E85 can take more timing than even pump gas + meth.
Thread Starter
Safety Car
Joined: Aug 2004
Posts: 4,734
Likes: 232
From: Youngstown Ohio
It does seem like that 30% is thrown around as an average, I have read it multiple times from lots of places. Looking at some MPG for E85 compatible cars from the factory that looks to be about right. For modified applications though it seems like the drop has mostly been larger and the tune issue is a whole other story.
Been a good read but it's time for me to get on with sleeping,
PC
Been a good read but it's time for me to get on with sleeping,
PC
Drifting
Joined: Mar 2011
Posts: 1,412
Likes: 15
From: Richardson TX
Lots of misinformation in this post. I see 30% get thrown around a lot when people are thinking about switching to e85 in regards to loss of fuel economy. This is relatively accurate on stock-ish low power motors. If you ever actually use the pedal on the right in your car it WILL be worse than 30% UNLESS you find a tuner that's comfortable disabling your O2 sensors and tuning your car to like 16-17:1 air fuel ratio at idle and cruise, which not a lot of people like to do.
Also the thing about two tunes is completely false, especially when going back to pump gas from E85. 1-2 gallons is not going to make enough of a difference for it to be a worry.
The biggest concern between switching between two tunes is that E85 can take more timing than even pump gas + meth.
Also the thing about two tunes is completely false, especially when going back to pump gas from E85. 1-2 gallons is not going to make enough of a difference for it to be a worry.
The biggest concern between switching between two tunes is that E85 can take more timing than even pump gas + meth.
Also, I know 1-2 gallons doesn't matter, but the point is you have to wait until your gas light comes on to change from E85 to regular. I meant that you can't just causally put whatever you want into your gas tank, and filling it up with something different at 1/4 tank is probably not safe.
Burning Brakes
Joined: May 2009
Posts: 793
Likes: 3
From: Scotland UK
30% is fair because it's simple chemistry. Subsidized or not, the E85 pricepoint never even breaks even to pump petrol. Unless you're comparing it to race fuel, it's not worth looking into for the $/gal incentive alone. The price for a new pump and injectors would buy a whole lotta meth.
Safety Car
Joined: Jan 2008
Posts: 4,797
Likes: 52
From: Boise
30% is fair because it's simple chemistry. Subsidized or not, the E85 pricepoint never even breaks even to pump petrol. Unless you're comparing it to race fuel, it's not worth looking into for the $/gal incentive alone. The price for a new pump and injectors would buy a whole lotta meth.
If you aren't running e85 and never have, please don't contribute to this thread with things you have read on the Internet. There is so much misinformation out there when it comes to e85 and a lot of it comes from people doing searches and reading the blind leading the blind.
Burning Brakes
Joined: May 2009
Posts: 793
Likes: 3
From: Scotland UK
WOT doesn't matter when comparing apples to apples. That's an independent variable that comes down to the driver. To make the statement that E85 is oxygenated is simply restating my FACT that it's simple chemistry. Ethanol is an alcohol and has oxygen and thus requires less air for a complete burn. How much? The diff between 14.7:1 and 9.6:1.... about 30%.
Safety Car
Joined: Jan 2008
Posts: 4,797
Likes: 52
From: Boise
Okay so if I take a completely stock vehicle, adjust the fueling by exactly 30%, the tune will remain 100% spot on, according to you, right?
So you are saying because of chemistry, no other variables need to be taken into consideration?
How many e85 cars have you tuned? How many cars running e85 do you own?
Btw....splitting hairs here but since you seem to believe everything is exact, using the stoich of 9.6 for e85 (which is incorrect btw), you are consuming 35% more fuel, again, because of chemistry.
So you are saying because of chemistry, no other variables need to be taken into consideration?
How many e85 cars have you tuned? How many cars running e85 do you own?
Btw....splitting hairs here but since you seem to believe everything is exact, using the stoich of 9.6 for e85 (which is incorrect btw), you are consuming 35% more fuel, again, because of chemistry.
Last edited by Milan; Jun 21, 2013 at 05:25 PM.
Burning Brakes
Joined: May 2009
Posts: 793
Likes: 3
From: Scotland UK
Of the variables, the driving variable is the stoich. I was consistent with my _about_ 30% to account for this and it's still a valid percentage to use for the price point comparison. Nowhere have I stated that changing the AFR in your tune will get you exactly where you need to be. My 9.6 value was just off the top of my head due to not being at a comp; I probably should have rechecked before posting it and causing someone blind to blow their engine up...
Rather than argue what my definition of about is, how much variance from stoich ratios, with everything else being the same, have you experienced?
Rather than argue what my definition of about is, how much variance from stoich ratios, with everything else being the same, have you experienced?
Le Mans Master
Joined: Jul 2010
Posts: 5,986
Likes: 719
So on the wideband what are you gunning for 9.6 afr that = 14.6 reg gas?? So if your running boost is it safe to say your target afr with E85 is 6.6 on the WB?? 14.6 at idle on regular fuel then in boost i run 11.0 so that's a 4.6 diff. Is it the same with E85 a roughly 4.6 diff on the WB???? Just curious i tryed e85 a few yrs ago never spent the time to get tune 100% because i was going through so much of it. My car is a Daily driver it was just sucking the fuel. I can see if my car was a weekend worrier it would be nice to use but everyday it was'nt saving me any money at all. From what i can remember it costed more to run e85 then gas and meth.
Last edited by helga203; Jun 22, 2013 at 08:05 AM.
Burning Brakes
Joined: May 2009
Posts: 793
Likes: 3
From: Scotland UK
An O2 sensor speaks in lambda, then based on how the gauge ouput is setup, displays an AFR. If you do not reconfigure your wideband gauge ouput from gasoline, 14.7 remains 1 lambda.
Last edited by Its Bruce; Jun 25, 2013 at 04:37 PM.
Drifting
Joined: Apr 2009
Posts: 1,898
Likes: 9
From: Morrisville PA
It will be safer for sure...you will see a very large hit in MPG. E85 is not fuel for budget conscious people, unless you are comparing to race gas.
You will need multiple fuel pumps and much larger injectors, and a tuner who knows how to tune on E85. A good question to ask is if he adjusts the stoich value, if he says no then you find another tuner.
You will need multiple fuel pumps and much larger injectors, and a tuner who knows how to tune on E85. A good question to ask is if he adjusts the stoich value, if he says no then you find another tuner.