Ethanol: why?

If you live in U.S.A. probably heard about how Brazil have coped imported oil dependency investing in ethanol as a fuel for its cars.
I´m afraid the people has not told you all the truth.
Yes, it´s true Brazil has nominal authonomy in oil and the ethanol helped it a lot but it is definitivaly not a easy way for follow; the program has more than 30 years over here and it is based in very specific points of my country. Despite it, bigger part of this authonimy as garanted by producing oil, not ethanol.
First; the total comsuption of oil in Brazil is about 1,7 million of barrels per day and the ethanol that is used daily is equivalet to 200 thousands of barrels of oil, basically as cars´ fuel.
The energetic matrix in U.S.A. is a lot different but if we don´t consider this will realize the size of it is too big for change quickly. They use about 20 million barrels daily and if start to burn ethanol in the same proportion Brazil does this will need about 2,35 million barrles of oil equivalent.
The biggest produce of ethanol, yes yet Brazil, makes about 15 billion liters every year. For provide the amount the U.S.A. would hipotetically need in this case 12 Brazils wouldn´t be enough.
The ethanol would be very scarce and the prices very high, and the main reason the people is given to adopt this as fuel is the high prices of gas.
Second; Brazil had when started the program - and still has - not utilized lands to grow its for-ethanol crops. In the U.S.A. any favoured crop will substitute other one, depends on the sell value of them. Instead foreign oil dependency maybe foreign corn or sugar cane dependency.
Does all this mean U.S.A. should´t adopt ethanol as a combustible?
No, this doesn´t. U.S.A. should adopt this but gas prices is the worst reason.
It can be used for ecolocical reasons, for estrategical reasons ad until for economical reasons but before defends it everyone should read more about it, don´t swallow the ethanol producers´ speach as they pray this.