Ethanol

• Fuel Economy: Since ethanol contains 34% energy than gasoline, there it will cause a 34% reduction in a vehicle's fuel economy. For E10, this effect is not very significant (3% reduction). This effect on E85 is significant. It will produce lower mileage than gasoline and will require refuelling more frequently.
• Greenhouse Gas Emissions: Recently, a study concluded that using ethanol only reduces greenhouse gas emissions by 0.13%. However, when you take into account the amount of carbon dioxide consumed by plants when one is producing biomass, the overall carbon dioxide emission drops significantly.