Methanol and Alcohol require about twice as much fuel as gas. 14.7 to 1 is the optimum mixture for gas and with alcohol it is about 6 to 1.
Methanol and Alcohol have very high octane rating and produces very good power when set up right but mileage is TERRIBLE!
In my race car I used about a gallon of gas per pass, when I switched to Alcohol I used about 2.5 gallons per pass but it was MUCH faster with no other changes. Alcohol also runs cool so it allowed me to almost eliminate my cooling system to save weight helping performance even more.

If my thinking is right (I could be wrong) a 10% Ethanol mix should hurt your mileage about 5%. My problem here is we do not know which ones have Ethanol or not. All pumps at all stations say "May contain up to 10% Ethanol" But nobody I have asked knows if or how much. So for my testing I try to use the same grade gas from the same gas station so atleast I am trying to compare apples to apples.

 

Now that's interesting.
If I understand what you are saying, adding Ethanol to gas can give you more power, thus the higher octane rating, BUT will decrease mileage.
Of all the things I have heard (and my past beliefs)That makes the most sense.

 

here in tampa you cant go to a gas station that doesnt have ethanol. I personaly am not a fan of it... My mpg has dropped and performance seems off.

 

I do not know if it will help or hurt performance with Ethanol but it will hurt mileage. For it to help the performance the computer would need to add a lot more fuel. I do not know how well the O2 sensor corrects for or with Ethanol. If it does not compensate for the alcohol it will hurt mileage and performance. E85 in a gas motor could run it lean and burn pistons if extra fuel is not added. Add extra fuel mileage goes way down but there is the potential for better performance. Alcohol is very corrosive and rusts most everything and it destroys many different types of O-rings to.
Alcohol does not light off easily in cold weather so it is very difficult to get your car started wen it is below about 40*.
Also Alcohol really works best with higher compression or boost so on a low compression motor even if richened up it may not help performance as much.
Another problem with alcohol as the volume of it you have to use. If your street car was to run on pure alcohol you would need about 50 gallon tank in your car just to have a decent fuel range. That would add a bunch of weight further hurting perfomance and mileage. Or you would have to fill up all the time. A gallon of Alcohol does not put out as much energy or BTU's as gasoline does but since it takes so much more alcohol you end up with more when it is at the right mixture.
So in my opinion there is nothing better than alcohol for race cars and it is the worst for daily drivers. Generally Ethanol is 10% or less alcohol so the changes are not as drastic but still there.

 

Eh! According to a Canadian study ethanol doesn't burn any greener either.

http://www.cbc.ca/canada/manitoba/st...emissions.html

 

As you said, it takes twice as much alcohol then gas..so in the case of stock street cars, all it does is displace the amount of gas available, it does nothing otherwise.To take advantage of alcohol, one would have to be "tuned' for it. Higher octane means you can "add" in more timing without the "knock" or detonation.On modern computer controlled cars your stuck with the factory tune on reg gas unless you go aftermarket or stage upgrades from the dealer.Thus you cannot take advantage of the higher octane ratings,unless, your already operating on the fringes and the higher octane smooths this out.Not all vehicles are alike despite being the same make model.This is why some models operate better on high numbered gas even though it recommends lower grade while the guy next to you can operate on low grade with no problems.Confused yet?

 

Here is a very interesting article on Ethanol mileage. http://ecomodder.com/forum/showthrea...bers-5790.html

He is saying a 10% Ethanol is up to 30% mileage loss.

 

Somethings not correct about that quote if in fact, you provided that accurately. It is well documented through testing, by the DOE...vehicle manufacturers....and the ethanol association group themselves that E-85 (85% ethanol) computes to a 27-30% drop in mileage. How can a lesser quantity of ethanol, 10%, compute to the same loss of mileage?

I'm not questioning the loss of mileage overall, only the numbers that are stated. I AM NOT A SUPPORTER of ethanol, in it's current state of supply. But I do request legitimate/valid information.

And curly.....if in fact your source is stating those numbers, I would be highly suspect of the rest of the content (Iwill read it later, when more time is available).

 

I just said it is interesting reading. I said he is saying 30% loss from 10% Ethanol. My personal opinion is that it is more than the 3% DOE and the manufacturors claim but less than the 30% that guy is claiming.

I can not verify that here because all of our gas pumps just say "May contain up to 10% Ethanol" We do not know which ones have it and which ones if any do not. I do know I have got some strange mileage numbers from time to time that did not make sense.

I do believe that E85% has to be more than a 27%-30% drop as those numbers just do not add up. Pure Alcohol takes almost 2.5 times as much fuel so 85% should be much worse than 27-30% in my opinion. Or a considerable loss in power or a combination of the two. If they are running it lean on E85 they are taking a chance of hurting the motor.

 

Just to throw in my 2 cents worth. If you knew you were going to run only ethanol, then you could build a motor that was optimized for it, with VERY high compression. The efficiency gained by the higher CR would largely offset the loss in btu/lb of the fuel itself, so the big problem is that the carmakers need to produce motors that will run on everything from 100% gasoline to 100% ethanol (in many cases) and can't bump up the CR to take full advantage of the ethanol properties.