Brazil’s domestic ethanol economy is now firmly established, but the process of building this economy was not always smooth. After a number of false starts, it has been the promotion of flex-fuel vehicles over the past decade which has perhaps been the most important factor in the success of ethanol. In recent years, ethanol consumption has grown rapidly, driven by the roll out of flex-fuel vehicles, which have benefited from tax breaks.

Source:

http://scientificregio.wordpress.com/2010/06/15/brazil-a-biofuel-success-story-part-ii/