Why Is E85 Hard To Start In Cold

If you’ve ever tried to start your car in cold weather and it just won’t turn over, you know how frustrating it can be. But when you’re using E85 fuel, cold weather can make starting your engine even more difficult.

So why is E85 hard to start in the cold? The answer lies in the ethanol content of the fuel and the effect that cold temperatures have on your fuel system.

E85 fuel is a blend of ethanol and gasoline, with the ethanol content typically ranging from 51% to 83%. Ethanol has a lower energy density than gasoline, which means it requires more fuel to produce the same amount of power. This can make it harder for your engine to start, especially in cold weather when the fuel is thicker and more viscous.

In addition, ethanol is hygroscopic, which means it absorbs moisture from the air. This can cause problems in cold weather when the moisture can freeze and clog fuel lines and injectors, making it even harder to start your engine.

Understand the Ethanol Content of E85 Fuel

If you’re frustrated by the fact that your car won’t start in the cold, it could be because of the high ethanol content in E85 fuel. Ethanol production has increased over the years, leading to greater use of E85 fuel.

E85 fuel is a blend of 85% ethanol and 15% gasoline, which is why it’s also called flex fuel. The high ethanol content in E85 fuel can cause issues when it comes to starting your car in cold weather.

The reason why E85 fuel is hard to start in cold weather is due to the ethanol’s environmental impact. Ethanol has a lower boiling point than gasoline, which means that it vaporizes more readily. In cold weather, the ethanol in E85 fuel can vaporize too quickly, making it difficult for the engine to start.

This is because the fuel injectors in the engine can’t deliver the right amount of fuel to the engine because the ethanol has vaporized too quickly. This can lead to the engine misfiring or not starting at all.

The Effect of Cold Weather on Fuel Systems

When driving in cold weather, it’s important to be aware of the potential effects on your fuel system.

Fuel line freezing can occur when the temperature drops below the freezing point of the fuel, causing a blockage in the fuel line. This can lead to engine stalling or difficulty starting.

In addition, cold weather can also impact battery performance and increase strain on the starter motor.

Fuel Line Freezing

Despite its benefits, E85 can be challenging to start in cold weather due to fuel line freezing. This occurs when moisture in the fuel system freezes and obstructs the flow of fuel. The fuel lines become clogged, preventing the fuel from reaching the engine. This can lead to hard starting, misfires, and even stalling.

Preventing fuel line freezing is essential to ensure your vehicle runs smoothly in cold weather. One of the best ways to do this is by using fuel additives. These additives help prevent moisture from freezing in the fuel system, allowing the fuel to flow freely. They also help keep the fuel system clean and protect against corrosion.

When choosing a fuel additive, it’s essential to pick one that is compatible with E85 fuel and designed for use in cold weather. By using fuel additives, you can ensure your vehicle starts smoothly in cold conditions and runs efficiently throughout the winter months.

Battery Performance

To get the most out of your vehicle’s battery, you’ll want to pay attention to how you drive and maintain it regularly. A weak battery can cause starting problems in any type of fuel, including E85.

In cold temperatures, the battery’s performance can decrease due to the chemical reactions that take place inside it. This is because the chemical reactions that happen inside a battery slow down as the temperature drops, which reduces the amount of power it can deliver to the engine.

To combat this problem, you can help your battery by following some simple maintenance tips. Regularly checking and cleaning the battery terminals and cables can help improve the connection between the battery and the engine. Additionally, engine tuning can help optimize the use of the battery, reducing the amount of power it needs to deliver to start the engine.

By paying attention to battery maintenance and engine tuning, you can help ensure that your vehicle’s battery is operating at peak performance, even in cold temperatures, making it easier to start your car, whether you’re using E85 or another fuel type.

Starter Motor Strain

If you’re driving a vehicle that runs on E85, you may notice that the starter motor has to work harder than usual, which can put a strain on it over time. The reason for this is because E85 has a higher octane rating than regular gasoline, which means it requires more energy to ignite.

This causes the engine to turn over more slowly, putting more pressure on the starter motor to get the engine going. To prevent starter motor wear and tear, it’s important to perform proper starter motor maintenance. This includes checking the battery connections, ensuring that the starter motor is properly lubricated, and checking for any signs of wear or damage.

Additionally, fuel injection troubleshooting may be necessary to ensure that the fuel system is working properly and delivering the correct amount of fuel to the engine. By taking these steps, you can reduce the strain on your starter motor and ensure that your vehicle runs smoothly, even in cold weather.

Precautions to Take in Cold Weather

When it’s cold outside, you should always make sure to warm up your engine before attempting to start it on E85 fuel. This is because E85 fuel does not vaporize as easily as regular gasoline, and it needs to be at a certain temperature to ignite properly.

One way to warm up your engine is to use an engine block heater. This device is designed to keep your engine warm and ready to start, even in the coldest of temperatures. By plugging it in a few hours before you plan to start your engine, you’ll ensure that the fuel is warm enough to ignite and that your engine doesn’t suffer from unnecessary strain.

Another precaution you can take in cold weather is to use fuel additives. These additives are designed to help E85 fuel vaporize more easily, which makes it easier to start your engine. They can also help prevent fuel line freeze-up, which can be a common problem in cold weather.

By using fuel additives, you’ll be giving your engine the best chance of starting smoothly, even in the most extreme cold weather conditions. So, if you want to keep your engine running smoothly during the winter months, make sure to take these precautions before starting your car on E85 fuel.

Other Factors That Can Affect Cold Starting

Now that you know how to prepare your vehicle for cold weather, let’s dive deeper into why E85 is hard to start in cold temperatures. Aside from the precautions we’ve discussed earlier, there are other factors that can affect your car’s cold starting ability.

One of these factors is engine oil viscosity. In colder temperatures, your engine oil thickens, making it harder for the engine to turn over. This is especially true for E85, which has a higher ethanol content than regular gasoline. Ethanol has a lower energy density, which means it requires more energy to start the engine.

If your engine oil is too thick, it can also affect the performance of your spark plugs. This is because a thicker oil can cause the spark plug to work harder, which can lead to suboptimal combustion.

Another factor that can affect E85’s cold starting ability is the condition of your spark plugs. If your spark plugs are worn out or dirty, they may not be able to generate enough spark to ignite the fuel mixture. This can lead to misfires and reduced engine performance.

It’s important to regularly check and replace your spark plugs to ensure your engine is running at its best. Overall, it’s important to be aware of these factors to ensure your car starts smoothly in cold weather.


Now that you have a better understanding of why E85 can be difficult to start in cold weather, it’s important to take the necessary precautions to prevent any issues from arising.

Firstly, make sure to keep your fuel tank as full as possible to prevent any water buildup in the tank. Additionally, using a block heater or engine blanket can help warm up the fuel system and make starting easier.

It’s also important to keep in mind other factors that can affect cold starting, such as battery health and oil viscosity. Regular maintenance and monitoring of these components can help ensure optimal performance in cold weather.

By taking these precautions and staying on top of maintenance, you can avoid any potential issues and keep your E85-powered vehicle running smoothly even in the coldest of temperatures.