Here's why it's difficult and what would be involved:
* Fuel System Compatibility: E85 is significantly more corrosive than gasoline. Many components in a standard gasoline fuel system (fuel lines, fuel pump, fuel injectors, seals, etc.) are not designed to withstand the ethanol content of E85. These parts would need to be replaced with E85-compatible components.
* Engine Tuning: The engine's computer (ECU) needs to be reprogrammed to adjust fuel delivery, timing, and other parameters to properly handle the different characteristics of E85. E85 has a lower energy density than gasoline, meaning the engine needs more of it to produce the same power. This requires precise calibration. Simply using an aftermarket E85 fuel system without properly tuning the ECU can severely damage the engine.
* Sensor Calibration: Additional sensors might be needed to monitor ethanol content and adjust fuel delivery accordingly. These sensors need to be properly calibrated and integrated into the ECU's system.
* Material Compatibility: E85 can affect various seals and gaskets within the engine and fuel system. These would likely need to be replaced with compatible materials.
* Cost: The cost of parts and professional labor for a proper flex-fuel conversion can easily exceed the value of many vehicles, making it an economically unwise choice.
In short: While theoretically possible in some cases, converting a gasoline car to flex fuel is a highly complex, specialized undertaking that typically requires extensive mechanical knowledge and specialized equipment. It's far more practical and cost-effective to purchase a vehicle that's already factory-equipped for flex fuel operation. Attempting this conversion without proper expertise could result in serious engine damage and potentially safety hazards.
