I guess I'll play devil's advocate here -- yes, I've run E85 in my CJ. BUT -- and this is a BIG but -- if you do this, it must be run ONLY on E85 after the conversion has been done. Yes, it requires all rubber components being removed from the fuel system. It would also be good to completely flush your fuel tank, so any sediments left do not get dissolved with the ethanol and sucked up into your fuel pump.
Ethanol (more specifically, E85 -- lets be honest, this isn't straight alcohol) may or may not get worse mileage than gasoline. Yes -- the engine requires 30-40% more fuel delivery, but there is also more power made once the engine is
tuned properly. This is the downfall that some people make and think "meh, I can just pump a tank full of E85 and roll with it." The stoichiometric mix of gasoline vs. E85 are quite different -- lambda for gas is approximately 14.7 parts of air to 1 part of fuel, and E85 is approximately 9.75 parts of air to 1 part of fuel. Basically, you need less air per part of fuel, or more fuel per part of air. This
may require larger fuel lines and/or a higher volume fuel pump, but
absolutely will require re-jetting the carburetor.
Now, tuning the carb for E85 isn't quite as simple as just throwing 30-40% larger jets in it and going to town. There are several passages that need enlarged, to include idle feed restrictors, tuning of emulsion bleeds, and tuning whatever type of WOT enrichment the carb has, whether it be power valve channel restrictors, or a fuel metering rod, or what have you.
Lastly, because of the combustion characteristics of E85, the ignition timing can be changed. Because E85 has a
lower combustion temperature than gasoline, it provides a cooler intake charge, letting the engine run cooler and make more power at the same time. The timing curve can be more aggressive, given the higher octane (~105) of E85. Initial timing can be advanced, as the timing all-in can be higher.
After a non-flex type vehicle has been converted to run on E85, it must stay that way unless it is converted back to gasoline. To go back to gas, you wouldn't have to switch fuel lines and/or pump, though. The carb and timing must be returned to how they were tuned for gas.
Hope this helps. Sometimes I love throwing a wrench into the mix.
