Is it possible to convert a vehicle that was designed for gasoline to operate on E85?
Yes and No. It is technically possible, however, there are no conversion or aftermarket parts that have been certified by the EPA as meeting the standards to maintain clean exhaust emissions.
Technically speaking, converting a vehicle that was designed to operate on unleaded gasoline only to operate on another form of fuel is a violation of the federal law and the offender may be subject to significant penalties.
No aftermarket conversion company has taken the initiative to certify an E85 kit that would allow a gasoline vehicle to operate on 85% ethanol.
http://www.iowacorn.org/ethanol/ethanol_5.html