Gasohol / Ethanol

[Trotbot]

I live in a country where 10% ethanol fuel ('gasahol') is available at mainstream gargages and 20% compatable cars are being launched. There is a lot of confusion as to the facts, so,

1. What does the addition of ethanol actually do? What is the maximum and the preferred concentration?

2. Do cars need to be adapted to avoid damage?

3. If yes to (2), what damage can be caused and what is the adaption process?

[aeroman]

This type of fuel is called bioethanol. It's not so popular now, 'cause it's too expensive to produce it, and moreover the engines are not compatible with it.
http://himzakaz.net/bioetanol