Gas Stations that have BAD Fuel

[Weather Spotter]

bingo! if the car is designed to use E10 it will have a higher compression ratio, and just change the timing if it gets E0. Some cars run better with E10 (mine).

[redpoint5]

Originally Posted by Weather Spotter

redpoint5, where is your source? The burden is on you to prove your numbers (ethanol is not guilty until proven otherwise).

Here, as well as any other website you might find:
Exact Low Energy Content of Ethanol

Originally Posted by TheEnemy

Actually red is correct pure ethanol has about 66% the energy of regular gas.

The problem with his statement is that we are running E-10, the difference in energy between E-10 and E-0 is only about 3.5%. So if your getting 50mpg, you should loose only 1.75mpg. Some cars like one of mine lost more because they don't seem to like E-10 for some reason or another.

One thing to keep in mind is if you are running E-100 you would have an octain of 122, in which you could run a much higher compression and possibly more than offset the lower energy per gallon.

Ethanol - Wikipedia, the free encyclopedia

Formula 1 car, yes please. MPG be damned. Actually, an efficient car could probably be made using pure ethanol for the very reasons you mentioned. It would be interesting to see how far that technology could go, although I don't think it can make up for the 1/3 energy density hit.

[Weather Spotter]

Good article. Its the BTU numbers that matter as octane is just a knock rating.

A. 76,000 = BTU of energy in a gallon of ethanol
B. 116,090 = BTU of energy in a gallon of gasoline
C. .655 = 2/3 = GGE of energy in a gallon of ethanol. A / B.
D. 1.53 = Gallons of ethanol with the energy of 1 gallon of gasoline. D = B / A.

How much should you pay for E10 and E85?

If regular gas is $3.00/gallon you should pay
$2.90 / gallon for E10 (10% ethanol).
$2.13 / gallon for E85 (85% ethanol).
If regular gas is $2.00/gallon you should pay
$1.93 / gallon for E10 (10% ethanol).
$1.42 / gallon for E85 (85% ethanol).
Then you will be paying the same amount per mile driven.

The formula is this: For EX, where X is the percent ethanol

Ethanol price should = Gasoline price times (100 – X + X/1.52)/100

[Frank Lee]

BTU content does NOT directly translate to BSFC! You say ethanol has 33% less energy BUT I challenge you or anyone else to prove that results in an exactly 33% fe reduction. Cuz it DOESN'T. Ethanol is an oxygenated fuel and burns a bit differently.

[ShadeTreeMech]

Originally Posted by Frank Lee

BTU content does NOT directly translate to BSFC! You say ethanol has 33% less energy BUT I challenge you or anyone else to prove that results in an exactly 33% fe reduction. Cuz it DOESN'T. Ethanol is an oxygenated fuel and burns a bit differently.

I have a '97 Merc Villager that gets between 20-21 mpg. When I ran e-85, I managed 17+ mpg (17.4 I think). My algebra is a bit rough, but e-100 would have netted 13.2 mpg, so 17 mpg isn't bad.

I ran e-85 in my 98 Maxima (remember, neither one is an official "flex fuel" vehicle, just fuel injected.) I got 22 mpg, when I was getting about 25 mpg. This figure is a bit unreliable since I was stuck in a bad traffic jam for a while on this and I was running the AC pretty heavy. Again, nowhere near the 33% reduction; it was actually a decent tank. I had a vacuum leak at the time, and that made things a bit rough in that it kept dying on me. AND I wasn't on an economy run, more like a lets get our butts home ASAP run.

While it may have less energy to burn, it does burn a bit differently, and may offset its lower energy content with a slightly more efficient burn per available BTU.

[redpoint5]

I LOVE anecdotal evidence, conclusions come so easily with them. The site I liked to has wonderful anecdotal stories of getting exactly the calculated mileage based on energy content.

I have made NO statements about what mileage to expect from running ethanol. Instead, I simply stated some facts for people to consider. Further, I have conceded that the higher octane should allow for efficiencies that exceed the calculated energy mileage.

My worthless anecdotal story is the greater than calculated drop in MPG when Oregon mandated E10.

I was initially excited about ethanol as a fuel, but the more I learn about it the less enthusiastic I become.

[Frank Lee]

Originally Posted by redpoint5

FYI- ethanol contains ~2/3 of the amount of energy as gasoline. This means an engine running 100% ethanol would get only 66% of the MPG that a gasoline engine would.

Originally Posted by redpoint5

I have made NO statements about what mileage to expect from running ethanol. Instead, I simply stated some facts for people to consider.

If you say so

[euromodder]

Looking at the fuel logs of some Volvo flexfuel cars, their real-life FC is between 15% and 30% worse on E85 than it is on regular gasoline.

[Phantom]

This could be tested somewhat easily by running a gas powered generator with a pre-measured amount of of fuel. Warm up the generator let sit for ~5min run with 1/8gal of gas time from startup to empty, do the same with E10 and E85. Calculate the difference in time to get the change in FE, the FE will not be in mpg but idle run time.

[ShadeTreeMech]

problem with using a carbureted engine for this expirement is that the carb isn't set up for alcohol, while a fuel injected vehicle will adapt to the fuel to an extent. I somehow doubt a carbed engine can run on e-85 without being adapted to it.

And I think euromodder is about right on the 15-30% decrease in FC; I personally saw a decrease of 15% running the stuff compared to regular gas.