E85 is an alternative fuel with 85% ethanol and 15% gasoline. However, it is widely reported that E85 vehicles have difficulties to start in winter and have poor performance. Here we report that with proper application of electrorheology, we can solve these issues. E85 vehicles all have port injected engines. The fuel is injected into cylinders as droplets. Before the ignition, the fuel evaporates. Because E85 is more viscous than gasoline, the injected E85 droplet size is not small. Especially, in winter the cold weather makes the viscosity even higher, leading the E85 droplets even bigger. Since evaporation starts from the droplet surfaces, large droplets are difficult to be evaporated before the ignition comes. When there are no enough fuel vapors, the engine cannot start. To solve this problem, we introduce a small device just before the fuel injection, which produces a strong electric field to reduce the fuel viscosity, leading to much smaller fuel droplets in atomization. The evaporation is much faster and the engine is easier to start. As the small fuel droplets produced by our device make the combustion fast and timely, engine efficiency and performance are also expected to be improved.