3.8.2: Environment- Gas

You may have noticed "E85" gasoline selling for $2.39/gallon for FlexFuel vehicles while regular gas was selling for$2.79. Is E85 use advantageous if you have a FlexFuel vehicle capable of using either E85 (85% ethanol) or regular gas? Note that many states sell regular gas that is E10 (10% ethanol) for standard (non-FlexFuel) vehicles.

 85% Ethanol at a modern pump The model T was first designed to run on ethanol[1]

There are really (at least) two questions here:

1. Is it a good deal for the consumer (is energy from ethanol economical)?

2. Is it a good deal for the environment (is the Energy Balance favorable)?