You can run higher compression ratios with alcohol but it does not change anything that it still requires almost 2.5 times more alcohol than gas. Many race cars are using 17 to 1 compression you could not do that on any motor that would run gas and Ethanol. Would run good on Ethanol but self destruct with gas.
Yes, if you designed a car to run on only Ethanol you could run higher compression. Alcohol does produce more torque so you could possibly use a smaller motor to offset some of it. Still you would end up with worse mileage and or worse performance. Bottom line is there is nothing good about Ethanol / Alcohol / Methanol in a street car. The higher the percentage the worse it gets.
There are also other problems such as you have to have larger fuel tank (more weight) more corrosive, and it absorbs moisture from the air and the fumes can be terrible. Also it is very bad about getting water in the oil or washing down the rings. There are ways to get around some of those problems but you can not get around the fact it requires more fuel.
There is nothing that makes Ethanol good for a street vehicle. Great for race cars but I can not see any benefits for a street car.

 

Plus..if you've ever been around alcohol cars..its always started with a shot of gas to get the cylinders firing.Straight alky doesn't like the cold. Its a diluter of gas when used at the pumps..serves no purpose then to offset the amount of real gas in a given gallon. Consider where its used in performance other then primary fuel...as a cooler (injected water alky mix) to obtain highr boost/timing and or compression with out detonation..because it "slows down" the burn rate of gas( which by the way is what octane does).Which is why it takes twice as much to make he same BTU's as gas.And as Curly said..its very hard on oil, it washes down the cylinders and dilutes the oil. And in pure form is a danger to handle...just watch any F1 race.

 

Well here is another one of my opinions and I do not know this for a fact only my opinion for what it is worth. There are somethings I know about Alcohol and some I do not.
I believe Alcohol is not as volitale or explosive as gas so in that respect it is safer. Alcohol burns cooler and slower than gas. But it does burn clear or a very light blue flame with no smoke and gas burns bright orange with black smoke so you can see it much easier. Not being able to see the flames can be dangerous.
When you are in a race car at 150 plus MPH there is no good fire.

 

I come from Subie community and we tested e85 and ethanol in general on turbocharged vehicles. Generally we found that the factory ecu can compensate for up to 33 percent ethanol by volume. When one considers that most unleaded sold is 10% ethanol than you can run a third of your fuel tank full of e85 and ecu will compensate for the extra amount of oxygen in a mix and one can save $3 per fill up in comparison with full tank of premium, plus one would end up with the tank full of 98+ octane fuel. I ran my 300+ hp Sti on 30% mix of e85 and the engine performed flawlessly, it ran smoother, less noisy with great power delivery across the range. Buschur racing is the company that tunes full e85 WRXs and Evos with great success and gets crazy power... And most modern vehicles have fuel lines and pumps suitable for ethanol.

 

dont know if this info applies exactly to this thread but i also think it has been addressed int his forum a little bit also. e85 causes about a 30% drop in efficiency because your engine has to use more fuel to get the same bang as gas(or iso-octane for our chemist{its mostly iso-octane}). overall in my opinion ethanol is what is killing our mpg over the us. i just want it to go away. and unless your car is setup to run ethanol(e85 to be exact) dont be pumpin a full tank of this into your car. it eats rubber and precaustions need to taken account for this.

 

I know this is an old thread, but since my HHR decision was partly based on OEM E85 compatability (vs. doing a fuel management modification) I wish to clear up some misunderstandings:

Ethanol boosts octane when mixed with regular gas. E85 is about 109, E100 is 113. It is used to replace MBTE which was used to boost octane before.
Ethanol does increase performance, and keeps your fuel system nice and clean, and burns cleaner at the tailpipe, but to burn at the air mixture of gas (since ethanol has more of its own oxygen) you need more fuel at a given air ratio and this is the only variable that NA cars can mess with currently. This is an increase in overall fuel consumption (but far higher gas mileage as a percentage of the fuel).
It is not an issue with turbo cars as you can simply up the pressure for the same mileage, but for NA applications on non-optimized engines (no variable compression) you burn more E85 than you do gas (and you get more power as a consequence).
On E10 there is no loss in mileage. Driving style makes the difference here.
On E85 there is an approximate 25% drop but if E85 costs 25% less its moot.
In either case your 'gas mileage' goes up because you are using less petroleum. On E85, the HHR goes about 109 miles per gallon of gas.
Because the engine is flex fuel, the engineers designed the 'penalty' to go to the E85 in terms of tank range, if the engine was optimized for the alcohol burn properties, there would be no penalty. You could get more power with less fuel, or just more power (see turbo apps). Those engines aren't here yet.

re: blends - check with your station, not all stations blend, some have 3 tanks in the ground (its a relic of leaded and unleaded fuels, they only sell midgrade because after the high test and cheap stuff, they have a tank in the ground and it would go to waste, some sell diesel others retrofit E85, the rest sell a mid grade - think of how much cheaper gas would be if the refineries only had to spend time refining 2 octanes not 3...)

re: ethanol % - in FL, I don't know about elsewhere, all stations have to have E10 at the minimum. No exceptions on vehicular (marine/aviation is different)

Seth

 

There are a few stations around here that sell non ethanol gas at a premium price (~$0.10/gallon) . I had read that they bring in marine grade gas (?). I have a tank of it my car now as I wanted to see if my milage improves in the HHR.

Prior to the mandated 10% ethanol, I was getting ~33-35 mpg in the HHR, but since the introduction, my mileage has dropped to ~29-31. I see the same drop in gas mileage with my other cars.

The Algore contingent has forced the 10% ethanol on the masses, which was just another ploy to subsidize the midwest corn farmers by growing corn for fuel, rather than corn for food. My political editorial comment.

 

Yes and The Algore contingent has made the price of feed and food go up by doing so !

 

Not to start a war or anything, but food v. fuel is a debunked myth. They are not diverting any food away by growing animal feed corn and refining it into a fuel and it has not caused any rise in overall food prices.
Because Ethanol competes with gas it has kept fuel and gas prices lower than they would have been had there been no alternative/competition.
The rise in food prices is due to higher demand for food (India/China) and the rise in fuel prices/cost of transport overall.

Seth

P.S. re: algore stuff - not everyone buys into ethanol for its environmental properties. Some like it because its not imported and is a local industry and is renewable.

 

The recent addition of a new station near my work allowed me to start using ethanol. I noticed a slight negative difference in the performance of the V6 engine in my Ford Escape, however the mpg went up by about 2 miles per gallon.