RE: E85 Conversion
I'm a huge proponent of E85, but your mileage will suffer dramatically. We had an '03 Grand Caravan that was a flex fuel van. Our mileage went from about 19-20 in town and 26-28 highway to about 12-14 in town and 20-22 on the highway. Synthetic fluids won't do a thing for your mileage.
It's not easy to properly convert your vehicle to run E85. Our Grand Caravan's engine hasa number of different parts from the factory, to include the injectors themselves, the entire fuel rail, the pressure regulator, etc. In my opinion, the kit referenced is a very poor conversion kit. It does not replace the injectors with larger-flow injectors. It does not replace any of the fuel lines. Regardless of what that website says, E85 DOES eat rubber. I am in the fuel tank business -- it costs a lot of money to change over dispensers and lines to remove all the rubber and aluminum components. All that conversion kit does is monkey with the reference signal to the injectors, and force them to feed more fuel through. That's not the right way to do a conversion kit! This kit does not talk to the factory PCM, so these two computers are working independent of each other trying to keep a correct A/F ratio.
If you really want to run E85, I would buy a flex fuel vehicle. Even as a huge fan and proponent of E85, I see nothing but trouble from these kits.
Edit: and don't count on the price of E85 staying low forever either. It's a commodity, just like gasoline. Government subsidies for the fuel won't last forever. If that fuel catches on in the mainstream, it'll be bought and sold and traded just like gasoline, and prices will begin to be affected by speculators and market traders, just as gasoline is.