What Is The Difference Between E15 And E85

If you’re curious about the difference between E15 and E85, you’re not alone. Both are ethanol blends that can be used as fuel for your vehicle, but they have distinct differences that can impact your vehicle’s performance and fuel economy. By understanding the differences between these two blends, you can make an informed decision about which one is right for your vehicle and your budget.

First, it’s important to understand what ethanol blends are and how they differ from traditional gasoline. Ethanol is a renewable fuel made from plant materials, such as corn, and it’s often blended with gasoline to reduce emissions and decrease our dependence on fossil fuels.

E15 is a blend of 15% ethanol and 85% gasoline, while E85 is a blend of 85% ethanol and 15% gasoline. While both blends contain ethanol, the difference in the percentage of ethanol can have a significant impact on your vehicle’s performance and fuel economy.

Understanding Ethanol Blends

You might be wondering how much ethanol is in your fuel, so let me break it down for you: E15 contains 15% ethanol, while E85 contains 85% ethanol, making it a much more flexible fuel option for your vehicle.

Ethanol is a renewable fuel source that’s made from crops like corn, sugarcane, and switchgrass. It has several benefits, like reducing greenhouse gas emissions and decreasing dependence on foreign oil.

The ethanol production process involves fermenting and distilling crops to create ethanol. The resulting ethanol is then blended with gasoline to create fuel.

E15 and E85 are both ethanol blends that offer a cleaner-burning alternative to traditional gasoline. E85 is particularly useful for flex-fuel vehicles that can run on either gasoline or ethanol blends, allowing drivers to choose the most cost-effective and eco-friendly option.

Vehicle Compatibility

If your car can run on regular gasoline, it may not be compatible with E85 fuel due to its higher ethanol content. However, E15 is a blend of gasoline and ethanol that contains 15% ethanol and 85% gasoline. Most cars manufactured after 2001 can run on E15 without any issues.

It’s still important to check your car’s owner manual or consult with a mechanic to ensure that your vehicle is compatible with E15 fuel. When it comes to fuel efficiency, E85 may not be the best option for all vehicles. While it may be cheaper than regular gasoline, its lower energy content can result in lower fuel efficiency.

Moreover, some vehicles may require engine modification to run on E85, which can be costly. Therefore, it’s important to consider these factors when deciding which ethanol blend to use for your vehicle. Ultimately, choosing the right ethanol blend can help you save money on fuel costs and ensure that your car runs smoothly.

Performance and Fuel Economy

When choosing between e15 and e85, it’s important to consider how each blend affects your vehicle’s performance and fuel economy. While e85 has a higher octane rating than e15, it also contains less energy per gallon, which can result in reduced fuel economy.

Additionally, the use of e85 may require engine modifications to handle the higher ethanol content, which can affect power output. Power output is a key consideration when choosing between e15 and e85. While e85 has a higher octane rating, it also contains less energy per gallon, which can result in reduced power output.

This is because ethanol has a lower energy density than gasoline, and engines may need to burn more fuel to produce the same amount of power. Additionally, the higher ethanol content in e85 may require engine modifications, such as larger fuel injectors or a different fuel system, to handle the increased alcohol content and maintain performance.

It’s important to consult with a qualified mechanic or tuner to determine if your vehicle is compatible with e85 and what modifications may be necessary.

Availability and Cost

The availability and cost of these ethanol blends vary depending on the location and demand. E15 is more readily available than E85 because it can be used in all vehicles made in 2001 or later.

On the other hand, E85 can only be used in flex-fuel vehicles, which aren’t as common as regular gasoline vehicles. The production methods of E15 and E85 also affect their cost.

E15 is made by blending 15% ethanol with 85% gasoline, while E85 is made by blending 85% ethanol with 15% gasoline. Since ethanol is cheaper than gasoline, E85 should be cheaper than gasoline, but because it’s only available at select locations, the cost can be higher.

Additionally, E15 has a higher energy content than E85, which means it can provide more miles per gallon, making it more cost-effective in the long run.

Environmental Impact

You’ll be amazed by the positive impact ethanol blends have on the environment. Ethanol is a renewable energy source that’s produced from corn, sugarcane, and other crops. It’s blended with gasoline to create E15 and E85, which are both cleaner-burning fuels than traditional gasoline.

These blends help to reduce carbon emissions, which are a major contributor to climate change. E15 contains 15% ethanol and 85% gasoline, while E85 contains 85% ethanol and 15% gasoline. Both blends are better for the environment than traditional gasoline because they emit fewer pollutants.

Ethanol is a cleaner fuel because it contains oxygen, which helps to burn the fuel more completely. This means that ethanol blends produce fewer harmful emissions like carbon monoxide and volatile organic compounds. In addition, ethanol is a renewable energy source that can be produced domestically, reducing our dependence on foreign oil.


In conclusion, understanding the differences between E15 and E85 can help you make informed decisions about which ethanol blend to use in your vehicle.

E15 is a gasoline blend that contains 15% ethanol and is compatible with most vehicles made in 2001 or later. On the other hand, E85 contains 51-83% ethanol and is only compatible with flex-fuel vehicles.

When it comes to performance and fuel economy, E15 is generally considered to be on par with traditional gasoline, while E85 can provide improved performance but lower fuel economy. Availability and cost are also important factors to consider, as E15 is becoming more widely available and typically costs less than E85.

Finally, it’s important to consider the environmental impact of ethanol blends. While both E15 and E85 can reduce emissions and dependence on fossil fuels, E85 has a greater potential to reduce greenhouse gas emissions. Ultimately, the choice between E15 and E85 will depend on your vehicle’s compatibility, your driving needs, and your environmental priorities.