One of the biggest problems that folks running a non E85 specific vehicle (Flex fuel) is that they do not realize the problems that come with it. E85 is comprised of basically alcohol, and has a burn rate of about 80,000 BTU, vs Gasoline with 120,000 BTU. It takes more E85 to produce the same power. Now with that being said if your fuel system was not designed for E-85 then you are going to have long term problems show up a lot sooner.
The US Govt has mandated the Military to run B20, the E-85 of the diesel world. You have no idea how much of a pain in the ass this has become in the maintenance of the vehicles. Fuel system clogs, injector replacements, fuel sender replacements and do not even get me started on the fuel filters we go through now. Seasonal equipment has been labeled as "Do not use B20" because if the stuff sits, organisms grow in it and they poo, and it clogs everything up. Then you have to add Biocide to all the tanks, and hopefully you kill the "gollywoggles"
In a gasoline application the same thing will start to show up, the alcohol in the systems will absorb water, and will rust the fuel systems out. Not only that but although you might be getting great boost levels, the stoichiometric values of gasoline are a lot different than alcohol and you will run lean over time. The ECU is not programmed for these new values, because your fuel system does not have the proper sensors to run the alcohol fuel. So while you may be getting a seat of the pants dyno feel of more power in essence you just may be destroying your engine, not to mention what this stuff is doing to your fuel system.
Do a lot more research on this before you go filling up your non flex fuel vehicle. Lots of good articles on this from bias folks, not the nay sayers, or the tree huggers.
Know what you are getting into before you have a pretty spendy repair on your hands.
What could happen if I use E85 in my non-FFV? My neighbor has used E85 in his non-FFV
for many months and he sees no problems. His car works great on E85.
• E85 reacts with certain materials in non-FFV engines causing them to be weakened or
fail and also has an oil washing affect on the cylinder walls. FFV engines and
components have been manufactured with the appropriate materials to handle these
affects and will not be damaged by E85 usage.
• Short term, there may be minimal affects and the vehicle may respond well to the
improved octane. Over time, a check engine light may be illuminated, the fuel filter may
plug, and the fuel pump may fail. At a minimum, you may have to have the vehicle towed
to a service facility and have the fuel tank drained, and fuel filter replaced.
• Long term affects of E85 in a non-FFV may be seen in premature failures of gaskets,
seals, valve seats, fuel system, piston rings and cylinder walls.