ethanol has been around for a while:its not some crazy new process--i believe its been a de-icer for plane control surfaces for a vey long time. E85 first i heard of it was the aforementioned mustang, which had to have been '00 or so, because the new body style was fresh and the thought of an eaton on a mustang was "far out" at the time.
how much this helps....???

 

Just a clarification...

Ethanol has been around since people invented stills, but the subject is E85, not ethanol.

I hadn't heard of it until recently either.

 

It's been available for years, maybe a decade even... mostly in the Detroit area where the big-3 test/R&D the concept.

All 3 use E85 for one or another reason. Many of the new models are deisgned to interchange between the two as well. To do this they use:

1) a sensor in the tank to determine what the fuel density is.
(between normal E10/gasoline, and the E85 there is obviously a "blend" tank that the system has to adjust to).

2) large fuel injectors.
While we use 24#/hour injectors on LT1's/LS1's... these vehicles have to deliver twice as much fuel to get the same hp... as a result the engine is spec'd for HIGH flow injectors than can scale down to low pulse-widths when running standard gasoline (aka E10).

3) Ethanol-prepped fuel system.
Removal of bare alumuinum from the fuel tank/lines/rails is required to prevent the same problem methanol-dragsters have: alcohol on aluminum can lead to a chalky corrosion. Usually this is means the tanks are plastic lined, and lines and fuel rails are stainless steel. Rubber gaskets ned to be replaced with inert materials as well, but the cost really isn't that great if you are starting with a new design... but converting over may be probelmatic. Low levels of ethanol have no problems like this, but once you pass about 20% ethanol you get into the area that you need to watch for this stuff. Hense the reason we won't see 20% ethanol gasoline for general consumption any time soon... though the 10 and 15% stuff is pretty common.

4) Timing advance.
Alcohol is known to be very forgiving with timning advance, and runs cooler than gasoline does... so you probably could run stock timing without problems, but I imagine it's such a shift in combusion properties that a good knock sensor/system is required just to make sure.

5) Dual O2's or maybe a wide-band O2, I dunno. There must be some way to adjust A/F ratio's, but a stock O2 sensor won't work as the stoich value of E85 is much lower than E10 or straight gasoline... similar situations as switching to diesel/methanol/propane... to go closed loop (almost a given for a new DOT-approved vehicle). I'd imagine they're going with a wideband sensor, but I honestly don't know for sure, that's just a best guess.