Ethanol vs Non-Ethanol Gas (Which is Better?)

Are you putting the right gas in your car? There are several different types of gas you can choose from when you visit a gas station. In addition to an octane rating, some fuels will offer different levels of ethanol content.

While most gasolines sold in the United States come with an ethanol content of at least 10%, non-ethanol gas or “clear gas” is still an option.

Although both fuels work in most gasoline engines, here are some differences you should be aware of when you go for your next fill up.

What is Ethanol?

Ethanol (also called ethyl alcohol) is a grain alcohol, typically derived from corn. Although most ethanol is manufactured from corn, it can be made out of nearly any fermented plant. Ethanol is sometimes made from sugar cane, grasses, or even fruits.

What Are the Benefits of Using Ethanol?

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Ethanol has many strong benefits over regular gasoline. Here are some of the biggest advantage to using ethanol instead of clear gas.

1) Renewable Resource (Better for the Environment)

Ethanol is much better for the environment than pure gasoline. Not only is ethanol renewable, it burns cleaner than gasoline, producing far less harmful emissions.

2) High Octane Rating

Ethanol has an octane rating of approximately 100 AKI, which is much higher than the 93 AKI you typically see at the pump. Higher octane means a fuel is more resistant to combustion under pressure.

Your car is less likely to knock when running higher octane fuel.

3) Less Dependence on Foreign Oil

Anyone can produce ethanol. In many places, it is even legal to brew your own ethanol. Government programs to introduce ethanol into the fuel supply can considerably reduce dependence on foreign oil. This could help keep fuel costs lower during economic downturns.

4) Runs Cooler

Ethanol runs cooler than pure gasoline. Since there is a lower energy content, more fuel is needed. Adding extra fuel gives the air fuel ratio a richer mixture, which helps cool the combustion chamber.

E85 is a fuel that is 85% ethanol, 15% gasoline. The combination of high octane rating and cooler operating temperatures make E85 a very attractive choice for performance applications. Race cars can safely be tuned for far more power running a fuel with a high ethanol content. E85 is also much cheaper than race gas.

5) Cheaper

Ethanol is very cost effective to produce. Running a fuel with ethanol in it will help you save money at the pump. Non-ethanol gas is often $1-2 per gallon more than standard E10 gasoline.

What Are the Cons of Using Ethanol?

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There are a few situations where ethanol may not be right for you. Here are some reasons why you might want to avoid ethanol at the pump.

1) Lower Energy Content than Gasoline

Ethanol has about 40% less energy content than gasoline. Since most gas stations offer E10 by default, this means the fuel will have about 4% less energy than non-ethanol gas. You will notice slightly reduced fuel economy when you run a fuel with ethanol in it.

2) Can Cause Corrosion in Carbureted Fuel Systems

While ethanol isn’t inherently corrosive, it draws moisture. This moisture can cause corrosion in older fuel systems that were not designed with ethanol in mind.

This is typically only an issue for older vehicles. Anything built within the last 30 years should be able to run E10 fuels without any long term problems. Corrosion in the fuel system was typically only a problem on older, carbureted engines.

3) Shorter Shelf Life

Since ethanol absorbs moisture, it does not have as long of a shelf life as pure gasoline. If you want to fill up a lawnmower or other gardening tool, you should consider using clear gas instead of E10. Those tools tend to sit for months without use during the off season.

Is Ethanol Good for Your Car Engine?

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Overall, ethanol is good for your engine if your car is designed to run it. Modern cars with gasoline engines are designed to run E10 with no long term drawbacks. However, you should be careful not to run a higher ethanol content unless you drive a Flex Fuel vehicle.

What is Flex Fuel?

Flex fuel is a vehicle that is designed to run gasoline with varying ethanol content, from E0 all the way up to E85 (and even E100 in certain countries).

Flex fuel vehicles have a variety of ECU calibrations along with an ethanol sensor. The ethanol sensor determines the ratio of ethanol to gasoline, and the ECU uses this data to select the best map for the type of fuel in the gas tank.

Brazil is one of the biggest manufacturers of ethanol, and offers 100% ethanol at many fuel stations. Many Flex Fuel vehicles sold in Brazil are designed to run this fuel safely.


Ethanol is pervasive across our fueling infrastructure, but it is nothing to be afraid of. As more research and development is conducted on synthetic fuels, the ethanol content offered in modern fuels may vary. As long as your vehicle is designed to run ethanol, you have nothing to worry about when you select unleaded E10.


4 thoughts on “Ethanol vs Non-Ethanol Gas (Which is Better?)”

  1. I have a 2022 Corvette with 2500 miles on it. It is now stored with a full tank of ethanol free fuel. I do not drive this vehicle in the winter months. Your recommendations for the summer months?

  2. We’re having a bit of an issue here, Our paperwork says 2.0L I4 which can run on regular fuel or flex fuel.. But our van is not equipped with the Yellow cap or filler hole. But follow the fuel tube down tot he tank, it shows there is a yellow adapter on the tank. I can’t get a straight answer from ford as to if our van is or isn’t a flex fuel or can run on the eFuels. 2 months ago, we tried a tank of the eFuel in the van and had zero problems other than we got poor gas mileage. It’s not that important if we can or can’t run the eFuels in the van. But I’d just like to know if we can if things were in a crunch.

    • You should be able to find that out by checking the VIN. Have you tried contacting a Ford dealership to verify that your vehicle is flex fuel capable?


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