* Poor performance: The engine may run rough, misfire, or lose power.
* Fuel system damage: E85 is corrosive and can damage fuel lines, seals, and other components not designed for its ethanol content.
* Sensor issues: The higher ethanol content can affect oxygen sensors and other engine sensors, leading to inaccurate readings and further damage.
If your fuel tank is half empty, the best course of action is to simply fill it with regular unleaded gasoline (the fuel your vehicle is designed for). Do not attempt to use E85 in a vehicle not specifically designed and approved for it.