How much does it cost to convert a car to run on ethanol?

The question for me is why? Ethanol is a horrible fuel to power autos. It is NOT more environmentally friendly than gasoline. Nor is it safer for humans to use than Gas. If your car got 20mpg on gas, it will get about 12mpg on ethanol, as ethanol has about 40% less power/gallon than gasoline. Ethanol also takes more power to produce than it produces when used as a fuel. While corn products are not the only source for ethanol, it is a primary source, and corn is better used as a fuel for humans than vehicles.