In one of the more frustrating arguments, ethanol proponents argue that producing gasoline is actually less efficient than producing ethanol. This is ludicrous on its face.
Here is a typical argument that producing ethanol is more efficient than gasoline. Minnesota department of Agriculture propagates this fallacy here.
To produce 1 btu of energy in ethanol, (1.67 btu returned to 1 btu used), it would take .6 btu's to produce 1btu of ethanol. This system has a 40% efficiency rating.
To produce 1 btu of energy of gasoline from crude, it takes .2 btu of energy, for an 80% efficiency.
But the Argonne National Laboratory is cited to show false scientific data as shown here. They show that ethanol has a 1.67% return on energy used, and that oil has a .8% net energy return. These numbers are inaccurate because they show two different statistics. It is true that producing gasoline from oil is an 80% efficient process. However, the 1:1.67 return is a measure of energy used versus energy returned. Oil, therefore, would be 1:4 return (based on returning .8 btus on a .2 btu investment). This is a very large difference.
For ethanol to be taken seriously, the arguments for its use must be accurate.