Common ethanol fuel mixtures

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Common ethanol fuel mixtures

- What blends mean
- Ethanol blends are shown as E followed by a number. The number is the percentage of ethanol by volume.
- Examples: E5 (5% ethanol), E10 (10%), E15 (15%), E85 (85%), E100 (neat ethanol).

- E5 to E25
- These are low-ethanol blends used in many countries.
- E10 is the most common and is usable in many modern cars without engine changes.
- E5 and E7 are considered safer for older engines.

- E10
- A 10% ethanol mix with gasoline.
- Often approved for use in most new cars without modification.
- Can improve octane and reduce some emissions, but may raise evaporative emissions in some cases.

- E15
- 15% ethanol and 85% gasoline.
- In the United States, a waiver allowed E15 for many 2007-and-newer vehicles, but not motorcycles or older cars.
- Infrastructure and warranty concerns have limited widespread adoption.
- Some stations use blender pumps to offer E10, E15, E30, and E85.

- E20 and E25 (Brazil and others)
- Brazil widely uses E20 to E25 as the standard gasoline blend, with engines already adapted.
- Brazil’s flex-fuel vehicles can run on blends from E20 up to E25 or on neat ethanol (E100) in some cases.
- Hydrous ethanol (water-containing) is common in Brazil; some vehicles can run on E100 or higher ethanol blends with specific starting systems.

- hE15
- A 15% hydrous ethanol blend (water-containing) used in some places like the Netherlands.
- Dehydrated ethanol adds costs; hydrous ethanol can be used in certain blending applications with adjustments.

- E70 and E75 (winter blends)
- In cold weather, ethanol content is reduced to improve cold starting.
- E70 or E75 blends are used in the United States and Sweden for winter operation.
- Some regions require engine heating or other measures for very cold weather.

- E85
- A common high-ethanol blend (85%) for flexible-fuel vehicles (FFVs).
- Octane around 108; widely used in the U.S. and Sweden for FFVs.
- Winter blends (like E70) can be used in some areas to ease cold starts.
- Availability depends on local fueling infrastructure; thousands of stations exist, but coverage varies by country and region.

- ED95
- A blend of ethanol with ignition improver used in modified diesel engines.
- Used in Sweden’s ethanol buses and other demonstrations in Europe and Brazil.

- E100 (neat ethanol)
- Pure ethanol used in cars designed to run on ethanol only.
- In Brazil, hydrous ethanol has historically been used in neat-ethanol vehicles, and newer flex-fuel designs can use blends ranging from E20 to E27.5.
- Starting systems in cold weather may rely on a small gasoline reservoir or engine-warming methods in some designs.

- E85 and weather
- In cold weather, some places use lower ethanol content (Winter E85, or E70) to help with starting.
- Some regions require engine block heaters for very cold conditions.

- Availability by country (highlights)
- United States: E10 standard; E15 pilot programs; E85 available in many states (Midwest); California has restrictions; blender pumps exist in some areas.
- United Kingdom: E10 became standard in 2021.
- Sweden: All 95-octane gasoline is E10 since 2021; E75 winter blend used in some FFVs.
- Brazil: Long-running use of E20–E25; large share of vehicles are flexible-fuel and can use E100 in some setups.
- Thailand: E20 and E85 have been introduced; E20 expansion has faced supply issues.
- India: Target reached to blend 10% ethanol (as of 2022).
- Other countries: Many have E5–E10 blends or are testing higher blends; winter blends and regional mandates vary.

- Pros and cons
- Pros: Reduces dependence on imported oil; can lower certain pollutants and greenhouse gas emissions in the right conditions; supports renewable fuel use.
- Cons: Higher ethanol content can reduce energy density and fuel economy in some cases; older engines and some equipment may need changes or may experience material compatibility issues; infrastructure costs are needed to support higher-ethanol fuels; in some conditions, evaporative or other emissions may increase.

- Engine and vehicle notes
- Most modern gasoline engines can handle low to moderate ethanol blends without major changes.
- Higher blends (above E10) may require flexible-fuel vehicles or engine and fuel-system adjustments.
- Ethanol blends can affect rubber, plastics, and some metals in fuel systems; manufacturers often specify which blends are safe for each model.
- Ethanol can lower tailpipe CO emissions and sometimes CO2, but the results depend on the engine, vehicle, and climate.

- Safety and restrictions
- Ethanol blends are not recommended for aircraft.
- E15 and higher blends require clear labeling and sometimes restrictions on which vehicles can use them.
- Some automakers warn that warranties may not cover damages from using higher ethanol blends in non-approved vehicles.

- Quick takeaway
- Ethanol blends range from small amounts (E5) to very high (E85, E100). They are used differently around the world, depending on vehicle technology, fuel infrastructure, climate, and government policy. When choosing a blend, consider your vehicle’s compatibility, the local availability, and how the blend affects performance and emissions in your area.