Is E85 Good in Cold Weather?

You may have heard that E85 causes problems in cold weather. This guide explains what U.S. government fuel data and automaker guidance say about using E85 in winter.

Is e85 good in cold weather?

E85 can be used in cold weather, but only in a flex fuel vehicle (FFV), and it has trade-offs. E85 sold in colder months usually contains less ethanol and more gasoline so engines start more easily. Even so, an FFV can crank longer in very cold weather, and it gets roughly 15% to 27% fewer miles per gallon on E85 than on regular gasoline all year. E85 is not approved for gasoline-only vehicles, and it is not sold at every station.

In this article, you’ll learn everything you need to know to answer the question, “Is e85 good in cold weather?”

What Is e85? (Simple Definition)

E85, also called flex fuel, is a high-ethanol fuel made for flexible fuel vehicles (FFVs). It is not approved for gasoline-only vehicles.

Despite the name, E85 is a blend of 51% to 83% ethanol with gasoline, according to the U.S. Department of Energy. The exact amount depends on the region and the season. FFVs are built to run on gasoline, E85, or any mix of the two. Because FFVs look like gasoline-only models, the surest check is the owner’s manual or the flex fuel guide on fueleconomy.gov.

If you cannot confirm that your vehicle is an FFV, do not fill it with E85.

E85 has some benefits, but there are a few things to keep in mind. First, ethanol has less energy per gallon than gasoline. FFVs get roughly 15% to 27% fewer miles per gallon on E85 than on regular gasoline, according to fueleconomy.gov.

FFVs are built with an ethanol-compatible fuel system, so E85 does not need special care in a vehicle designed for it. Follow the maintenance schedule in your owner’s manual.

Finally, E85 is not available in all areas. The U.S. Department of Energy’s Alternative Fuels Data Center lists more than 4,200 public E85 stations in 44 states and has a station locator.

If you are looking for an alternative to gasoline that is renewable and domestically produced, e85 may be a good option for you. Just be sure to do your research and understand the pros and cons before making the switch.

What Are the Downsides of E85 in Cold Weather?

E85 has a few downsides that matter more in winter.

Those reasons include:

• e85 gets a lower gas mileage per gallon
• e85 can take longer to start in very cold weather
• e85 is not available everywhere

One of the main disadvantages of E85 is lower gas mileage. FFVs get roughly 15% to 27% fewer miles per gallon on E85 than on regular gasoline. E85 is typically cheaper per gallon than gasoline but slightly more expensive per mile.

Cold weather also lowers fuel economy in every vehicle, whatever the fuel, so expect to fill up more often in winter.

Additionally, e85 is not always available at all gas stations, so you may have to plan your route carefully if you want to use this type of fuel.

Another downside is that high-ethanol fuel can be harder to start in very cold weather. An engine needs fuel vapor to start, and the Alternative Fuels Data Center notes that E85 sold during colder months often contains lower levels of ethanol to produce the vapor pressure needed for cold starts.

One example: a General Motors service bulletin says 2014 Chevrolet Silverado 1500 and GMC Sierra 1500 trucks running E85 could crank for 3 to 10 seconds at 0°F (-18°C) or colder.

Once the engine is running, drivers should notice no loss of performance on E85 in a flex fuel vehicle, according to fueleconomy.gov. E85 should never be used in a vehicle that is not built for it.

It is important to weigh these factors before deciding whether or not to use this type of fuel.

What Are the Advantages of Using E85?

E85 is not all bad.

E85 has a number of benefits over gasoline:

• E85 lowers tailpipe emissions of CO2 and of some toxic pollutants such as benzene, although it raises acetaldehyde emissions, according to the Alternative Fuels Data Center.
• E85 has a higher octane rating than regular gasoline, and many FFVs accelerate better on higher ethanol blends.
• An Argonne National Laboratory analysis found that using corn-based ethanol in place of gasoline cuts life cycle greenhouse gas emissions by 40% on average.

E85 is typically cheaper per gallon than gasoline, but because it delivers fewer miles per gallon it usually costs slightly more per mile.

E85 should only be used in flex fuel vehicles. It is not approved for gasoline-only models.

What Temperature Is Too Cold for E85?

There is no single cutoff temperature for E85. Fuel suppliers lower the ethanol content in colder months so flex fuel vehicles can start, and the blend changes by region and season.

There’s no easy answer, but there are some things to consider.

The clearest guidance found for this article comes from General Motors. A 2014 service bulletin for the Chevrolet Silverado 1500 and GMC Sierra 1500 says the starting characteristics of E85 make it unsuitable when temperatures fall below 0°F (-18°C). Check the owner’s manual for your own vehicle, because guidance differs by make and model.

At those temperatures the engine may crank noticeably longer before it starts.

This does not mean E85 is always a bad choice in cold weather. Apart from lower miles per gallon, FFV drivers should see little difference between E85 and gasoline, according to the Alternative Fuels Data Center.

A factory flex fuel vehicle does not need a special winter tune. It is designed to run on gasoline or any ethanol blend up to 83%.

If an FFV is slow to start on E85 in very cold weather, adding regular gasoline to the tank or using an engine block heater may help. If the problem continues, have a dealer or mechanic check it.

Is e85 Hard to Cold Start?

It can be. High-ethanol fuel is harder to start in very cold weather, which is why E85 sold in winter contains less ethanol.

This video from the YouTube channel OverTQed Garage shows one owner’s cold start on E85. It is one person’s experience, not a controlled test:

If you’re driving a flex-fuel vehicle that runs on e85, it’s important to take some extra steps to prevent cold starting problems.

One way to do this in a flex fuel vehicle is to add regular gasoline at the pump during the coldest months. An FFV can run on any mix of gasoline and E85. Never add E85 to a gasoline-only vehicle.

More gasoline in the mix makes the fuel easier to turn to vapor, so the engine starts more easily. The fuel is not at risk of freezing: ethanol freezes at about -173°F (-114°C). Another option is an engine block heater, which warms the engine before starting. Follow the vehicle maker’s instructions for using it.

Parking in a garage keeps the engine warmer before a cold start. Never leave the engine running inside a garage attached to a house, even with the garage door open, because exhaust contains deadly carbon monoxide. Start the car, then drive off gently after about 30 seconds.

Is e85 Good in Freezing Winter?

As any Midwesterner or Northerner knows, winter can be brutal.

Frigid temperatures and bone-chilling winds are the norm, and it’s not uncommon for the mercury to dip below zero.

For drivers who use E85, winter can mean longer cranking on very cold mornings.

Automaker guidance is cautious. General Motors has told technicians that E85 is unsuitable for starting below 0°F (-18°C) in the trucks its bulletin covered, and that adding regular gasoline or using a block heater may help. Check your owner’s manual for the advice that applies to your vehicle.

Are e85 Winter Blends Myth or Fact?

Winter blends are a fact, not a myth.

Fuel suppliers change the ethanol content of E85 by season and region under the ASTM fuel specification. Summer blends tend to have more ethanol and winter blends have less, so the fuel makes enough vapor to start a cold engine.

These changes also affect gas mileage. The less ethanol in the blend, the smaller the drop in miles per gallon compared with gasoline.

Drivers do not need to ask for winter fuel. Stations are expected to supply the winter blend, and the Alternative Fuels Data Center notes that they must blend down any remaining summer fuel to meet the winter specification.

Can You Mix e85 with Gas in the Winter?

Yes, but only in a flex fuel vehicle. FFVs are designed to run on gasoline, E85, or any mix of the two. Do not put E85 in a gasoline-only vehicle in any amount.

Regular gasoline already contains some ethanol in most of the U.S. E10, which is 10% ethanol, is approved for any conventional gasoline vehicle. E15 is approved only for model year 2001 and newer light-duty vehicles. Higher blends such as E85 are for flex fuel vehicles only.

Adding gasoline to E85 in an FFV lowers the ethanol content, which can make cold starts easier. It has nothing to do with freezing: neither fuel freezes at normal winter temperatures. More gasoline in the mix also means more energy per gallon, so miles per gallon improve as the ethanol share falls.

Mixing E85 with gasoline is not a guaranteed way to save money. E85 is typically cheaper per gallon than gasoline but slightly more expensive per mile.

E85 Winter Tricks

As winter approaches, it’s time to start thinking about how to keep your car running smoothly. A few extra steps can help a flex fuel vehicle start in cold weather.

Here are a few winter tricks for using e85:

• Install a block heater. This will help to keep your engine warm so that it starts more easily in the cold.
• Add some regular gasoline at the pump (flex fuel vehicles only). A lower ethanol content makes cold starts easier.
• Park in a garage if you can. This keeps the engine warmer before starting. Never leave the engine running in a garage attached to a house, even with the door open, because of carbon monoxide.
• Drink hot coffee. In cold weather, hot coffee is a great way to stay warm until your car starts.

These steps can make cold starts easier, but they do not replace the advice in your owner’s manual. If your flex fuel vehicle still struggles to start on E85 in very cold weather, switch to regular gasoline until it warms up.

Final Thoughts: Is e85 Good in Cold Weather?

E85 works in cold weather in vehicles built for it, because winter blends carry less ethanol to help engines start.

Expect fewer miles per gallon and possibly longer cranking on the coldest mornings. If your vehicle is not a flex fuel vehicle, do not use E85 at all.

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Sources

U.S. Department of Energy, Alternative Fuels Data Center (E85)
Alternative Fuels Data Center (E85 specification)
Alternative Fuels Data Center (ethanol blends)
Alternative Fuels Data Center (flexible fuel vehicles)
Alternative Fuels Data Center (ethanol vehicle emissions)
fueleconomy.gov (ethanol)
fueleconomy.gov (fuel economy in cold weather)
General Motors service bulletin via NHTSA (E85 cold starts)
CDC (carbon monoxide poisoning basics)

Reviewed October 2026. We corrected the ethanol content of E85 and the claims about freezing, cold starts, performance and mixing with gasoline, made clear that E85 is only for flex fuel vehicles, removed personal recommendations, and added a carbon monoxide warning, using the U.S. Department of Energy Alternative Fuels Data Center, fueleconomy.gov, a General Motors service bulletin and the CDC.