An engine is a combustible engine, not a gasoline engine. It will run on anything that blows up. Funny cars run on pure alcohol, {ethanol}. And they are a lot faster than the Gas class. In Brazil all the cars run on pure alcohol made from corn. They can't afford gas.
If the car manufactures built their engines with good parts like the racers do, ethanol would be no problem at all. You need forged engine parts to use ethanol. And rubber parts that aren't made in China. Remember the tires that were denigrating on people?
As far as the story I heard about there being to much water in the mixture that will ruin your engine, I have watched an engine run on pure water. In the 50s because of the expense of gas, rodders use to run a tube from the base of the carburetor to a bottle of water on the floor board to get better gas milage. The B25 bombers use to do that in WWII so they could travel longer distances. I have never had a problem with ethanol in any of my cars. If anything I'm sure it will keep your injectors cleaner. Stabil is a great product to use in your gas tank and Mystery Oil, which I have used for years.
Well, there's some good info here, and some stuff that is out of context, to say the least. It is true that an engine can be designed to run on many different types of fuels, but as a rule it's tough to design ONE engine that will run on a wide variety.
Yes, Alcohol has been used in racing engines for a long time. But they use METHANOL, not the ethanol that's in our gas. Methanol has a lower amount of chemical energy per pound that gasoline, but because it has high octane rating, you can run 14 or 16 to 1 compression, and so you extract the energy it has more efficiently. You also use more of it. As I recall, methanol carb are jetting around 6:1, not 14:1, air/fuel. A similar ratio applies to ethanol.
The real issue with ethanol is because ethanol is sort of, well, bisexual. It will mix with gasoline, and it will mix with water. If you mix ethanol and water it's called vodka. Add some food coloring and it's Jack Daniels's ;-)
Refineries have put very small amounts of either methanol or ethanol into gasoline for decades. It helps to control gas-line freeze-up. In cold climates, small amount of water settle in the lowest place in the fuel system, which is often the fuel line. Sometimes when the car is parked it freezes and plugs the line. A wee bit of alcohol, either kind, prevents this.
Here's the bisexual part: If you have gasoline that is 90% real gas and 10% ethanol, and zero water. All is well. But condensation in the tank, etc, means that a small amount of water will get into the system. If it remains small, no problem. But if the amount of water increases, at a certain point the ethanol decides it would rather be vodka than fuel, and it settles out of solution with the gas, and stays with the water. So now you have a gas tank that is maybe 85% fuel, and 15% vodka, and the vodka sinks to the bottom, and the fuel pickup grabs it, ands it doesn't burn. Or, it just rusts stuff.
Wanna play scientist? Pour 1 quart of 10 percent ethanol gas into a largish jar. Measure carefully. Begin adding plain water, about 1/2 teaspoon at a time, stirring well. The first few additions will blend, but when you get up to about 15 percent, all of a sudden the alcohol and water will come out of solution with the gas and settle to the bottom.
Rodders did not run a tube to a bottle of water because water burns. it does not. Water injection, or water-methanol injection, has been used for decades to cool the intake air so that you get more air, and therefore more power, and you also get a little more resistance to detonation. When water or methanol evaporate, they absorb a lot of heat. This is why alcohol on your skin feels cool, and it is the principle behind swamp coolers. Cooler air is denser, so there is more air per cubic foot. ESPECIALLY on a blown or supercharged engine, injecting the liquid can really cool the intake charge and reduce detonation problems. There is a downside - two, actually. Vaporized water, aka steam, occupies volume, so the more steam you let into the cylinder, the less air and oxygen you get. Second, hot steam is a pretty good oxidized, and it tends to eat away at metals, especially aluminum.
Older engines may not have ethanol-resistant seals and gaskets, etc. and of course that's an issue. But old or new, none of them like the excess water that accumulates. More of an issue on lawnmowers and chainsaws and such than on daily drivers.