The numbers favoring corn ethanol are those which ignore production, transportation, and refining costs of energy, and increased costs to consumers from cattle feed prices through to tacos. In other words these are the numbers cited that come from the "media" advisors for the ethanol producers. To be fair, some bio-fuels may be very cost effective, especially if used locally, to avoid significant transportation costs. I have even seen an "efficient" localized application of hydrogen for motor fuel and electrical generation, but in general use this would require a $5 to 6$ subsidy of energy for every BTU gallon equivalent produced.

Conservation, otherwise known as "prudent" consumption, is still the least cost way to improve our energy situation in the short term. I took the train to work today and saved almost $4 in gas, $9 in mileage depreciation, and $9 in parking.

Bob2