What Is The Difference Between E85 And E15

Are you looking for a more eco-friendly fuel option for your vehicle? If so, you may have heard of two popular options: E85 and E15. While both fuels contain ethanol and are designed to reduce emissions, there are some key differences between them that you should know before making a decision.

First, let’s define what E85 and E15 actually are. E85 is a fuel blend that contains up to 85% ethanol and 15% gasoline. On the other hand, E15 contains up to 15% ethanol and 85% gasoline.

While both fuels offer some similar benefits, such as reducing greenhouse gas emissions and supporting domestic agriculture, there are some important considerations to keep in mind when choosing which one to use.

Let’s explore these differences in more detail.

Definition and Composition of E85

You might be wondering what E85 is and how it differs from E15 – well, let me tell you! E85 is a fuel blend that consists of 85% ethanol and 15% gasoline. It’s primarily produced from corn, although sugarcane and switchgrass can also be used.

E85 is known for its high octane rating, making it an excellent option for high-performance engines. However, E85 production has an environmental impact that should not be overlooked. Although it’s a cleaner fuel compared to gasoline, the production process itself can result in increased greenhouse gas emissions. It’s due to the energy required to grow, harvest, and process the corn used in its production.

Additionally, the land use required for growing corn can contribute to soil erosion and water pollution. As such, it’s important to weigh the environmental benefits and drawbacks of using E85 as a fuel source.

Definition and Composition of E15

Feeling confused about which ethanol blend to use for your vehicle? Well, let me tell you that E15 has a higher concentration of ethanol compared to regular gasoline. Specifically, E15 is a blend consisting of 15% ethanol and 85% gasoline.

This ethanol blend is relatively new, having been introduced in 2011 as a way to increase the use of renewable fuels and reduce greenhouse gas emissions. E15 production involves a process called dry milling, where corn is ground up and mixed with water to create a mash. Enzymes are then added to convert the starch in the corn into sugar, which is then fermented by yeast to produce ethanol.

The resulting ethanol is then distilled and dehydrated to create a high-octane fuel that can be blended with gasoline. However, there are concerns about the environmental impact of E15 production, particularly with regards to the amount of water and energy required to produce ethanol from corn.

As such, alternative feedstocks, such as switchgrass or algae, are being explored as potential sources of ethanol.

Benefits and Drawbacks of E85

Now, let’s explore the advantages and disadvantages of using E85 as a fuel for your high performance vehicle.

E85 is a blend of 85% ethanol and 15% gasoline, which makes it a popular choice for those who want a cleaner and more renewable fuel option.

The primary benefit of using E85 is that it can increase your vehicle’s horsepower and torque, which is great for those who want to boost their vehicle’s performance. In fact, E85 is often used in high performance vehicles such as race cars and muscle cars because it can provide a significant increase in power output.

However, the drawbacks of using E85 are that it can decrease your vehicle’s fuel efficiency and range. This is because ethanol has a lower energy density than gasoline, which means that you will need to use more E85 than gasoline to travel the same distance.

Additionally, E85 is not as widely available as gasoline, which can make it difficult to find a gas station that offers this fuel.

Lastly, the environmental impact of producing and using E85 fuel is also a concern, as the production of ethanol requires a significant amount of energy and resources, and the use of ethanol can result in higher levels of smog-forming pollutants.

Benefits and Drawbacks of E15

If you’re looking for a fuel option that can provide a boost in performance without sacrificing fuel efficiency too much, E15 may be worth considering. E15 is a blend of gasoline that contains up to 15% ethanol, which is a renewable fuel source made from crops like corn.

The main advantage of E15 is that it can increase the octane rating of gasoline, which can improve engine performance and power. E15 can also reduce harmful emissions, which can help the environment by reducing air pollution.

However, there are also some disadvantages to using E15. One of the main drawbacks is that it can be harmful to certain types of engines, especially older vehicles and small engines like those found in lawnmowers and boats. E15 can cause damage to engine components like fuel pumps, fuel lines, and injectors, which can lead to costly repairs.

Additionally, E15 may not be available at all gas stations, which can make it difficult to find in some areas. Overall, while E15 can provide some benefits, it’s important to consider the potential drawbacks before deciding if it’s the right fuel option for your vehicle.

Choosing the Right Fuel for Your Vehicle

When choosing the right fuel for your vehicle, it’s important to check your vehicle manual for the recommended fuel type. This information can also be found on the gas cap or fuel door.

Additionally, consider fuel availability and cost in your area, as well as the potential impact on your vehicle’s performance and efficiency.

By taking these factors into account, you can ensure you’re using the best fuel for your specific vehicle.

Checking Your Vehicle Manual

Take a moment to flip through your vehicle manual and see what it says about fuel types, especially if you’re considering switching to E15 or E85. Your vehicle manual will provide information on the specific fuel types your vehicle can handle, and it’ll also indicate whether or not it’s safe to use E15 or E85.

It’s important to understand that not all vehicles are designed to run on these alternative fuel types, and using the wrong fuel can result in significant damage to your engine.

In addition to checking your vehicle manual, it’s also important to keep up with regular maintenance and follow fuel efficiency tips. Regular maintenance can help ensure that your vehicle is running efficiently, which can help to save you money on fuel costs in the long run.

Fuel efficiency tips, such as avoiding unnecessary idling and maintaining proper tire pressure, can also help to improve your vehicle’s fuel economy. By taking these steps and staying informed about your vehicle’s fuel requirements, you can help to ensure that you’re making the best decisions for your vehicle and your wallet.

Considering Fuel Availability and Cost

You’ll want to consider the availability and cost of fuel when deciding which type to use for your vehicle. E15 is more widely available than E85, and it’s usually less expensive. However, the fuel efficiency of E15 is lower than E85. This means that you’ll need to purchase more E15 than E85 to travel the same distance, which can impact the overall cost.

Another factor to consider is the environmental impact. E85 is often touted as a more environmentally-friendly option, as it produces fewer emissions than traditional gasoline. However, the production and transportation of E85 can still have negative effects on the environment. Additionally, E15 has a higher ethanol content than traditional gasoline, which can also contribute to a reduction in emissions.

Ultimately, the decision of which type of fuel to use should be based on your individual needs and priorities.


Congratulations! You’ve gained a better understanding of the differences between E85 and E15 fuels. Now, you can make an informed decision on which fuel is best suited for your vehicle.

E85 fuel offers several benefits due to its higher ethanol content. These benefits include improved engine performance, reduced greenhouse gas emissions, and potential cost savings. However, E85 has some drawbacks, including decreased fuel efficiency and limited availability.

On the other hand, E15 fuel has a lower ethanol content. This provides some environmental benefits and can still improve engine performance. However, it may not be compatible with all vehicles and its availability is limited as well.

When choosing the right fuel for your vehicle, it’s important to consider the make and model of your car, as well as the availability of the fuel in your area. Additionally, you should consider the environmental impact and cost savings associated with each type of fuel.

With this knowledge, you can make a decision that is both environmentally conscious and financially responsible.