What Happens If I Put 87 Instead Of E85

Have you ever wondered what would happen if you accidentally put regular gasoline (87 octane) in your vehicle that requires E85 fuel? It’s a common mistake, but one that can cause serious damage to your engine if not addressed properly.

E85 fuel, also known as flex fuel, is a blend of ethanol and gasoline that is designed to work in vehicles specifically designed to run on it. Using regular gasoline instead can cause a range of issues, from poor performance to complete engine failure.

Understanding the difference between E85 fuel and regular gasoline is crucial in order to avoid potential problems. E85 fuel has a higher ethanol content, typically ranging from 51% to 83%, while regular gasoline only contains 10% ethanol.

This difference in composition means that E85 fuel has a lower energy density, which can affect the performance of your vehicle. If you accidentally fill up with regular gasoline instead of E85, you may notice a significant decrease in power and efficiency.

But that’s not the only issue that can arise – read on to find out what else can happen and how to fix the problem.

Understanding E85 Fuel

If you put 87 instead of E85, you won’t be getting the benefits of using this high-octane fuel. E85 is a blend of ethanol and gasoline, with the ethanol content varying between 51% and 85%, hence the name.

The higher ethanol content in E85 fuel means it has a higher octane rating, which results in better performance and power. It also burns cleaner than gasoline, reducing harmful emissions that contribute to air pollution.

Compared to other alternative fuels, E85 has several benefits. It’s renewable, as it’s made from corn and other agricultural crops. It’s also domestically produced, reducing dependence on foreign oil. E85 also has a smaller carbon footprint than gasoline, making it a more environmentally friendly option.

However, it’s important to note that not all vehicles are designed to run on E85 fuel, so it’s important to check your vehicle’s owner’s manual before using it.

Potential Issues with Using Regular Gasoline

Using regular gasoline instead of E85 can cause some serious issues for your vehicle. One of the most significant effects is the reduction in engine performance. Regular gasoline has less ethanol content than E85, which means that it burns less efficiently. A less efficient burn leads to a decrease in power output and acceleration, making it harder for your engine to perform optimally.

Another potential issue with using regular gasoline in an E85-fueled vehicle is the damage it can cause to the fuel system. E85 fuel systems are designed to handle higher ethanol content, which is more corrosive than gasoline. Using regular gasoline can lead to the buildup of deposits in the fuel system, causing clogs and potentially damaging the fuel pump and injectors.

The cost comparison between E85 and regular gasoline also favors E85, as it’s typically less expensive per gallon and can provide better fuel economy. Overall, it’s crucial to stick to E85 fuel in your E85-compatible vehicle to avoid any potential issues and ensure optimal performance.

Signs That You’ve Used the Wrong Fuel

You’ll know you’ve used the wrong fuel when your vehicle starts to exhibit warning signs. One of the most common signs is a decrease in fuel efficiency. If you’ve been using regular gasoline instead of E85, you’ll notice that your vehicle is consuming more fuel than usual.

This is because the engine is not designed to run on regular gasoline and is therefore working harder to produce the same amount of power. Not only does this lead to increased fuel consumption, but it also puts more strain on the engine, which can lead to engine damage over time.

Another warning sign that you’ve used the wrong fuel is a decrease in engine performance. If you’ve been using regular gasoline instead of E85, you may notice that your vehicle is not accelerating as quickly or that it is not running as smoothly as it should be.

This is because regular gasoline does not have the same properties as E85 and is not able to provide the same level of power and performance. If you continue to use regular gasoline, the engine may become damaged and may require expensive repairs.

It is important to pay attention to these warning signs and to take action immediately to prevent further damage to your vehicle.

Steps to Fix the Problem

If you’ve accidentally used the wrong fuel, don’t panic. The first step to fixing the problem is to drain the fuel tank completely.

Next, replace the fuel filter to ensure that any remaining residue from the incorrect fuel is removed.

Finally, refill the tank with the correct fuel, in this case E85, to prevent any further issues.

Following these steps will help get your vehicle back on track and running smoothly again.

Drain the Fuel Tank

First, try to picture yourself underneath your car, using a wrench to remove the drain plug from your fuel tank. This may seem daunting, but it’s a necessary step to fix the problem of accidentally putting 87 octane instead of E85 fuel in your tank.

Once you remove the plug, the fuel will start to drain out, so make sure you have a container ready to catch it all. It’s important to note that draining your fuel tank yourself can be risky and may cause damage to your car if not done correctly.

If you’re uncomfortable with doing it yourself, it’s best to seek professional assistance. However, if you’re confident in your abilities, make sure to drain the tank completely until it’s empty, as even a small amount of the wrong fuel can cause damage to your engine.

Once you’ve drained the tank, refill it with E85 fuel and your car should be running smoothly again.

Replace Fuel Filter

To ensure your car is running at its best, it’s important to replace the fuel filter after using the wrong fuel. When you put 87 instead of E85, your fuel system is susceptible to contamination. The fuel filter is responsible for cleaning the fuel that flows into your car’s engine.

When contaminated fuel enters the engine, it can cause damage to critical components such as the fuel injectors and fuel pump. That’s why fuel contamination prevention is essential for keeping your car running smoothly.

Replacing your fuel filter is an essential step in fuel system maintenance. It’s recommended to replace your fuel filter every 30,000 miles or as soon as you realize that you’ve used the wrong fuel. A dirty filter can obstruct fuel flow, which can lead to decreased engine performance and even engine failure.

By replacing the fuel filter, you’re ensuring that your car’s engine is getting the cleanest fuel possible, which is crucial for optimal performance. So, if you’ve mistakenly used the wrong fuel, make sure to replace your fuel filter to maintain the longevity of your car’s engine.

Refill with E85 Fuel

Now that you’ve replaced the fuel filter, it’s time to refill with E85 fuel to get your car running at its best. E85 is a fuel blend that contains up to 85% ethanol and the remaining 15% gasoline. One of the benefits of using E85 is that it burns cleaner than regular gasoline, which means it produces less harmful emissions.

Additionally, ethanol is a renewable resource, making E85 a more sustainable option for those who want to reduce their carbon footprint. When comparing E85 to regular gasoline, there are a few things to keep in mind. E85 has a higher octane rating, which means it can handle more compression without detonating.

This can result in improved engine performance and better fuel efficiency. However, E85 also has a lower energy content than gasoline, which means you may need to refuel more frequently. Overall, if your vehicle is designed to run on E85, it’s worth considering as a fuel option. Just be sure to check your owner’s manual and make sure your vehicle is compatible before filling up.

Prevention Tips

Avoiding the mistake of filling your car with regular gasoline instead of E85 can save you from costly engine damage. This mistake can happen due to a number of common mistakes like not paying attention to the fuel pump label, being in a hurry, or having someone else fill up your car.

If you do make this mistake, there are emergency procedures you can follow to minimize the damage to your engine. To prevent this from happening, always double-check the fuel pump label before filling up your car. E85 pumps are usually labeled with a yellow hose and nozzle, while regular gasoline pumps have a black hose and nozzle.

Additionally, make sure to only use a gas can that is clearly labeled for E85 fuel. In case you do accidentally fill up your car with regular gasoline, do not start the engine and call a tow truck to take your car to a mechanic. Running your car with regular gasoline instead of E85 can cause serious engine damage, which can be very expensive to repair.


In conclusion, it’s important to understand the differences between E85 fuel and regular gasoline to avoid potential issues when filling up your vehicle.

Using regular gasoline instead of E85 can cause a number of issues, such as reduced fuel efficiency and engine performance. Additionally, using the wrong fuel can also cause damage to your engine, which can be costly to repair.

If you do accidentally use the wrong fuel, it’s important to address the issue as soon as possible. This may involve draining the fuel tank, cleaning the fuel system, and making any necessary repairs.

To prevent this problem from happening in the future, always double-check that you’re using the correct fuel for your vehicle, and familiarize yourself with the signs that you may have accidentally used the wrong fuel.

By taking these steps, you can ensure that your vehicle runs smoothly and efficiently, and avoid any costly repairs due to using the wrong fuel.