Is E85 for me? That's a question myself as well as Contributing Editor Chris Werner have been pondering as the use of an alternative fuel source in a high performance application, as well as the thought of cheap race gas, seems very appealing. On the surface, the 85% ethanol blend would seem perfect for a high compression motor or forced induction build given its 100-105 octane rating and latent heat of vaporization (cools the intake charge) as well as its price tag, which is usually any where from 20 or 30 cents to nearly two dollars cheaper than pump gas. As of late, it is even becoming more convenient to pick up E85–especially in metropolitan areas as more and more gas stations are carrying it.
On the other hand, you can expect 20-35% reduction in fuel economy, according to the government's "Fuel Economy Guide," because the energy content of E85 is 20-37% less than gasoline per-gallon. The real stumbling block, though, is compatibility. Non-Flex Fuel Vehicles, or vehicles not designed specifically for use with E85, can suffer any number of problems over time from fuel system failure and even engine failure, according to GM and the US Department of Energy, with the use of E85. In fact, the use of E85 in a vehicle that was not manufactured with the intent of its use is emissions illegal unless converted at an authorized facility. And unfortunately no conversion kits have been released onto the market for older vehicles anyways.
But since we are geeky tech types, and most likely so are you, we've been looking into what exactly it would take to convert a non-FFV. First, you would need a custom tune given that you will need to consume much more fuel due to the difference in stoichiometric AFR. Since ethanol can act as a detergent in washing lubrication away from parts, the motor would have to be built with that in mind...meaning careful selection of the piston rings, valve seals, valve seats, valves, etc. The fuel system (including the fuel rails, lines, filter, tank and pump) would need to flow a considerably larger amount and use materials which don't breakdown upon contact with ethanol (again the detergent factor). We hope to discuss specifically what all this means at a later date.