E85 Experiment

Messages
2,072
Location
GoVols
Thread starter
Fill up my tank today with E85 for the first time ever. I'll post later in the week with results of mpg change 👍
 
Messages
6,941
Location
The Midwest
How empty was your tank when you got E85? If you filled up at a 1/4 of a tank as an example, you cant give us real world results. Supposedly, E85 gets anywhere from 15-27% less MPG's than E10.
 
Messages
8,806
Location
MA
Originally Posted by skyactiv
How empty was your tank when you got E85? If you filled up at a 1/4 of a tank as an example, you cant give us real world results. Supposedly, E85 gets anywhere from 15-27% less MPG's than E10.
Well you just have to do the math. Ethanol has 76,100 btu's per gallon vs gasoline at about 114,000 and E85 is at 81,800. http://www.hho4free.com/gasoline_vs_ethanol.html Thing is, I believe E85 isn't always 85% ethanol, it could be a higher mix of gasoline so depending on the price, it might be a good deal and give you better mpg than expected due to higher gasoline concentration.
 
Messages
2,072
Location
GoVols
Thread starter
Originally Posted by skyactiv
How empty was your tank when you got E85? If you filled up at a 1/4 of a tank as an example, you cant give us real world results. Supposedly, E85 gets anywhere from 15-27% less MPG's than E10.
I was under 25 to empty So I was really low on fuel 36 gallon tank, I got almost 33 gallons of E85
 
Last edited:
Messages
1,077
Location
Wisconsin
BTUs alone don't determine fuel economy Modern high compression engines will run better timing and power on e85 Due to the vapor pressure inflection point e20-e30 will deliver (better than expected) fuel economy in any obdii engine
 
Messages
9,986
Location
Waco, TX
Originally Posted by Rmay635703
Due to the vapor pressure inflection point e20-e30 will deliver (better than expected) fuel economy in any obd-2 engine
Please explain this concept.
 
Messages
1,769
Location
Middle of Iowa
Originally Posted by Rand
E85 is usually somewhere between 51-83% ethanol. in the winter more "gas" is used.
not in Iowa...I believe we have a state mandated minimum of 70% year round.
 
Messages
2,072
Location
GoVols
Thread starter
Originally Posted by danez_yoda
What vehicle? Hopefully its rated for E85.
2018 Ford F-250 6.2L It's good for E85
 
Messages
2,072
Location
GoVols
Thread starter
Originally Posted by DriveHard
Originally Posted by Rand
E85 is usually somewhere between 51-83% ethanol. in the winter more "gas" is used.
not in Iowa...I believe we have a state mandated minimum of 70% year round.
Sticker on the pump stated minimum 70%
 
Messages
2,072
Location
GoVols
Thread starter
Two hundred miles into this tank Mix of city highway which is my normal Mpg down from 14.5 to 14.4 so far Need to run a couple tanks to get a better number
 
Messages
591
Location
Atlanta, GA
That actually is barely a drop in MPG for E85. I ran E85 almost exclusively in my old '09 MB C300 and the fuel economy hit was pretty significant in both freeway and city. Was rated 18/25 on 93 octane or 13/19 on E85, purely freeway trips would drop from 26-27 down to 20-21 and purely city commuting would drop from 15-16 down to 9-10. I kid you not some pretty horrific city mixed in I was seeing low 9 MPG, fuel light would come on with about 2 gallons left in the 17ish gallon tank. I was at the pump filling up A LOT when it was strictly city driving. LOL The cost spread between 93 and E85 made it still financially beneficial for me to run E85 the majority of the time. There were a handful of tanks where the spread made 93 a better proposition so it had a few tanks of 93 thrown in here and there.
 
Messages
2,072
Location
GoVols
Thread starter
Yeah So far I'm not seeing a big difference in mpg But from a performance side Butt dyno tells me it's a little stronger with E85
 
Messages
1,953
Location
North Carolina
Originally Posted by danez_yoda
What vehicle? Hopefully its rated for E85.
Why? My 2002 Silverado isn't rated to run E85 and it has been on it for over 3 years now with no issues.
 
Messages
1,943
Location
Kansas
Originally Posted by Rat407
Originally Posted by danez_yoda
What vehicle? Hopefully its rated for E85.
Why? My 2002 Silverado isn't rated to run E85 and it has been on it for over 3 years now with no issues.
Doesn't E85 eat away the plastics that weren't designed for that much ethanol content?
 
Messages
1,953
Location
North Carolina
Originally Posted by FordBroncoVWJeta
Originally Posted by Rat407
Originally Posted by danez_yoda
What vehicle? Hopefully its rated for E85.
Why? My 2002 Silverado isn't rated to run E85 and it has been on it for over 3 years now with no issues.
Doesn't E85 eat away the plastics that weren't designed for that much ethanol content?
It is my understanding that any vehicle manufactured after 2000 is ethanol capable. I could be wrong, but in my case GM was producing flex fuel vehicles back then so I suspect that anything that was coming down the line was already set up for E85, just that if it wasn't a flex fuel vehicle it didn't have the sensor to detect the ethanol and the ethanol table in the computer wasn't turned on. Case in point. Our 2016 Suburban isn't a flex fuel vehicle but there was a pigtail under the vehicle at the fuel tank where the sensor would have gone if it came from the factory. So I added a sensor, plugged it in and then had the vehicle tuned by Black Bear Performance, where the turned on the ethanol table in the computer. I sent a data log after they tuned it and they said was working and it showed a 36% ethanol in that tank of fuel.
 
Messages
3,561
Location
Central Iowa
Originally Posted by DriveHard
Originally Posted by Rand
E85 is usually somewhere between 51-83% ethanol. in the winter more "gas" is used.
not in Iowa...I believe we have a state mandated minimum of 70% year round.
Not quite. Depends on the labeling on the pump. The level of ethanol is allowed to fluctuate seasonally. I warmer season, 70% is the norm and if the pump is labeled such it is indeed required to contain a minimum of 70%. But many stations will switch labeling in the cooler months and show a "51% to 70%" number on the label. The state is pretty picky on how pumps are labeled and that the ratios match the labeling. Fuel is tested by the state fairly regularly. I live in central Iowa myself and use E85 exclusively in my Chevy pickup and Chevy Equinox.
 
Messages
3,561
Location
Central Iowa
The mpg loss, on the surface, can be disheartening. But if that is all one looks at, they may be missing out. It all depends on the price spread. And fuels have to be compared to similar fuels. Since E85 is a 100 octane fuel and a top level fuel used in the high performance community, it should really be compared to Premium gasoline. Let's see... according to Gas Buddy for my area, Premium fuel is going for 2.94 a gallon in Newton Iowa. Unfortunately Gas Buddy is not showing E85 price, but my wife filled her Chevy Equinox yesterday with E85 and it was $2 A gallon. So a 94 cent spread. The Nox seems to average about 22 mpg on E85 for all miles.... city, highway, rural gravel roads, etc. That means on E85, the cost per mile is roughly 9 cents a mile. The best it ever got on premium was about 26 mpg for all miles maybe 27 mpg if the wind was favorable. At 2.94 for premium, that equates to just over 11 cents per mile fuel cost. No thanks. I will stick with E85 and can easily live with the lower mpg. That 11.2:1 compression ratio 4 banger seems to function much better on E85 or premium than regular fuel it can use and the exhaust has far fewer deposits by using E85. Same for my 6.0 V8 Chevy pickup.
 
Top