Ethanol is a renewable fuel derived from a wide range of plant materials known collectively as “biomass.” Ethanol can be mixed with gasoline to create various blends.
Blends of E10 (10% ethanol, 90% gasoline) or less are used in more than 20 countries around the world, led by the United States. In 2022, India achieved its E10 target, and the country is working toward a target of 20% ethanol blend by 2025.
Although blended fuel has environmental benefits, but it reduces the vehicle mileage. The fuel economy of the blended fuel decreases with the increase in ethanol content. This is because ethanol contains approximately 34% less energy per unit volume than gasoline, and therefore in theory, burning pure ethanol in a vehicle reduces range per unit measure by 34%, given the same fuel economy, compared to burning pure gasoline.
The chart below shows the estimated mileage reduction for each fuel blend.
| Fuel Type | Mileage Reduction (%) |
| Gasoline (Baseline) | 0% |
| E10 | ~3% |
| E15 | ~5% |
| E20 | ~7% |
| E25 | 8-9% |
| E30 | 10-11% |
| E70 | 23-24% |
| E85 | 25-26% |