Skip to Content

Should You Put Ethanol-Free Gas in Your Tank?

Should You Put Ethanol-Free Gas in Your Tank?

Many gas pumps have various options for drivers, including ethanol-free gas. The one you put into your fuel tank can help your vehicle last longer and perform better. On the other hand, putting the wrong type of fuel in your car can cause severe damage. So should you put ethanol-free gas in your tank? Let’s see!

What Is Ethanol-Free Gas?

Let’s first understand what ethanol is. Ethanol is an alcohol, in fact, the same type you find in an alcoholic drink. The chemical structure is CH3CH2OH and the hydroxyl group (OH) bound to the carbon is what makes it alcohol. Ethanol is also flammable and carries significant energy.

Ethanol-free gas is gasoline that’s free of ethanol. Manufacturers only use petroleum products in the creation of this gas. The result is pure and more energy-rich gasoline. This can improve engine performance, fewer maintenance issues, and longer engine life. However, this type of gasoline typically comes with a premium price.

Truck hitched to RV parked at Walmart gas station
Ethanol-free gas is a more pure and energy-rich gasoline option.

Why Is Ethanol In Gasoline?

In 2005, the U.S. passed the Energy Policy Act and authorized the Renewable Fuel Standard (RFS) program. As part of this program, the government set minimum requirements for using renewable alternatives, like ethanol, in motor fuel. This has several benefits, including helping corn farmers, reducing prices at the pump, and lowering dependence on non-renewable oil, both from domestic and foreign sources. However, it sacrifices up to about 3% of fuel economy and increases smog pollution in hot weather, and some engines simply can’t handle higher blends.

Pro Tip: Time is running out for your to discover When Does Gas Expire and How to Make It Last?

How Do You Know If Gas Has Ethanol in It?

Any gas you get from a gas station pump without an ethanol-free gas label will contain ethanol. It’s why you see “E85” and “E15” labels on the pump. The number on the label represents the percent of ethanol in the gasoline mixture. As a result, “E85” gasoline contains 85% ethanol In the US E10 is the normal amount in gasoline if it’s not labeled otherwise.

However, you may have a gas can and wonder whether it has ethanol. The only way to be 100% sure is to test it. To do this, you’ll need a simple test tube or tester kit. Measure two inches from the bottom and place a mark on the side of the tube. Fill the tube with water up to the line you’ve created on the tube, and then top off the tube with the gasoline you want to test. Place a lid on the container and shake it a few times.

REV X E85 Super Tester Reusable Ethanol Testing...
  • Test your fuel for proper ethanol levels to ensure it does not...
  • Simple test to discover the percentage of ethanol alcohol in...
  • High levels of ethanol could damage your fuel system and lower...

The gasoline and water will mix and then separate as the mixture settles. Once the blend settles, look at the water level compared to the line on the side of the tube. If the fuel contains ethanol, the water level will increase. If you need ethanol-free gas and notice the water level has risen, do not use it.

Pro Tip: Want to save money at the gas pump? Find out Does Cruise Control Really Save Gas?

Should You Put Gas Without Ethanol in Your Tank?

Most modern cars can run on fuel with some ethanol in it just fine. However, older carburated engines or small engines do not tend to run as well on it. This has to do with the way combustion differs from gasoline and that ethanol can absorb water. Water in suspension can cause adverse effects on 2 stroke and engines without electronic ignition. However modern fuel-injected engines can easily adapt to the differences in fuel and have no problem with it.

While gas without ethanol typically results in increased fuel economy, it’s not always worth it. You may experience a slight increase in your MPGs, but you’ll likely notice the increased price at the pump. Ethanol-free gas comes with a premium price tag, typically $.30 to $1.00 more per gallon. As a result, if you’re worried about the cost of fuel, you’ll want to fill your tank with a gas containing ethanol. 

Our take is that ethanol-free fuels are best for performance vehicles, carburated vehicles, and small engines. Ethanol-free fuel is also a better choice if the vehicle does not run much and the fuel will be in the tank for a long time. Ethanol is not as stable as gasoline and can start breaking down in a few weeks.

Woman refilling car with gas that doesn't have ethanol
Gasoline labeled with an “E” and a number will contain some percentage of ethanol.

Is Ethanol Free Gas Better for Your Engine?

Yes and No. In most modern cars small amounts of ethanol have minimal to no effect on the engine. However, if the fuel has been stored for an extended amount of time it has a higher chance of going bad and clogging fuel filters or absorbing too much moisture.

Ethanol will also break down rubbers and seals that are not made for it. Most newer engines are designed with rubbers that can withstand it, but older vehicles may have seal and carburetor problems. Fuel lines and pumps can also suffer.

Overall ethanol-free fuel lessens the chance for damage in almost all engines, however, so you could say it’s better for it.

The only benefit ethanol has is its ability to absorb water. This may seem counterintuitive but running fuel with ethanol in it will prevent water separation buildup in your tank. This can prevent water from entering your fuel system which can cause severe damage. Even if you run a modern vehicle on ethanol-free because it’s better, an occasional tank of E10 is not a bad thing. We have been doing this for years after having water troubles in our boat gas tank. Now we store the boat with a full tank of E10 fuel and use fuel stabilizers. This combination has been great to prevent water buildup.

Pro Tip: Before you fuel up, uncover Premium Fuel: Myth vs. Reality – Is It Still Safe to Use in Any Car?

Trucks parked at gas station refilling car with gas without ethanol
Check with your vehicle’s owner manual to decide if ethanol-free gas is safe to use in your vehicle.

Is Gas Without Ethanol Better for Performance?

Ethanol-free gas can provide better performance and additional horsepower, especially in older vehicles. Ethanol contains 30% less energy than gasoline. However, some modern high-performance vehicles have engines for gas containing ethanol. You’ll want to check your vehicle documentation to avoid causing any damage.

Did you know? If you want ethanol-free gas in one of these states, you’ll have to tell the attendant. They won’t let you pump it yourself!

Will Gas Without Ethanol Hurt My Car?

Whether you accidentally or purposefully put ethanol-free gas in your car, you likely don’t have to worry. This gas will most likely not hurt cars. Many find that this gas is better for the engine and rubber components in the fuel system. However, you should always check your vehicle’s owner’s manual to use the fuel the manufacturer recommends.

types of gasoline at the fuel pump
Deciding which gas works best for your vehicle and budget will be up to you. However, ethanol-free gas can be a great option for your engine.

How Long Will Gas Without Ethanol Last?

Because gas without ethanol doesn’t attract moisture like gas with ethanol, it can last approximately six months when you store it correctly. You need to keep it in a non-spill container that is airtight and completely sealed.

Avoid placing this gas in direct sunlight or in a space that will experience sudden or drastic changes in temperature. Not storing your gas correctly will drastically reduce its lifespan and capabilities.

The best way to store fuel long-term is to use fuel stabilizers. These products can prevent fuel from breaking down and make sure the engine will run when restarted. Be sure to run the stabilized fuel into the engine however to make sure it’s in the whole fuel system.

Which Gas Brand Has Least Ethanol?

Because gas is a critical component of motors and could cause severe damage, it’s heavily regulated. Any gas brand that claims its gas is ethanol free must genuinely be ethanol free. 

Shell E15 Regular 88 contains 15% ethanol, and any other brand that sells E85 gasoline will have the same amount of ethanol. It’s common to see E85, E87, E89, and E93 at gas pumps. No matter where you’re buying the fuel, each location will have the same amount of ethanol.

Pro Tip: Have you heard of pranksters putting sugar in people’s gas tanks? Before you start to worry, find out will Sugar in Gas Tank Ruin Your Engine?

Is Ethanol Free Fuel Worth It? (With Results!)

Is Ethanol Free Gas Worth It?

There is no one-size-fits-all approach to using ethanol-free gas. Some vehicles and situations have a better experience using it than others. You’ll want to check your owner’s manual to see if you should use it in your vehicle. Some small engines like boats, lawnmowers, and generators will run much better on it. However, regarding everyday driving, most drivers won’t benefit from using ethanol-free gas because of the increased price.

Would you put this gas in your engine? Tell us in the comments!

Become A Mortons On The Move Insider

Join 10,000+ other adventurers to receive educating, entertaining, and inspiring articles about RV Travel Destinations, RV Gear, and Off-Grid Living to jump-start your adventures today!

About Mortons on the Move

Tom & Caitlin Morton of Mortons on the Move gave up the stationary life for one where they are constantly on the move. They are full-time travelers, television hosts, and digital media producers.
They left their jobs, sold their house and possessions, and hit the road in September 2015 in their full-time “home on wheels”. Since then they have traveled the US, Canada, and even internationally by RV.
Now, they are Discovery Channel & PBS TV Co-stars of “Go North” on Amazon Prime Video, co-founders and instructors of RV Masterclass, and contributing authors for and an Arizona travel guide.

About Us

Sharing is caring!

Walter Hinojosa

Sunday 9th of July 2023

I just filled up my car without ethonal gas and got 3 more miles per gallon. Plus I noticed that gas from different gas stations makes a different on gas mileage.

Mortons on the Move

Saturday 15th of July 2023

Most cars are tuned for regular ethanol 10% these days and run well on it. Personally i feel it only really causes problems at high altitudes.


Friday 19th of May 2023

Yes I have a 3.5 ecoboost every other 1/4 tank i put 93 oct with alcohol then 91oct alcohol free a blend I'm getting 24 mpg at 75 mpĥ in tx.

William Bauer

Friday 21st of April 2023

Before switching to ethanol free gas eight years ago, I had carburetor problems with my chain saw, string trimmer, gas blower and lawn mower. This required rebuilding/ replacing each device’s carburetor. Since changing to ethanol free gas, I have had NO further problems. Starting my mower this year, I pulled the rope twice and the engine fired immediately. I also use this fuel in my F150 6 cylinder turbo. No problems in nearly 7 years. I will use this fuel as long as it is available.

Walt G.

Wednesday 15th of March 2023

I only put ethanol free gas in my lawn equipment and portable generator. Before that and after the introduction of ethanol added fuel I started having running and starting issues with everything I owned except the automobiles. I became educated by small engine mechanics and switched to ethanol free. No more problems! In my Rv on my last fill up before home base I add fuel stabilizer and fill the tank . I run the on board generator to fill it with the stabilizer mixed gas. So far so good !

Tim Hannum

Sunday 25th of December 2022

I don't like the ethanol gas for all of the reasons you listed. You have to love our government for pushing it. Just saying...