Many drivers choose premium gas hoping to get the best performance from their vehicles. But a common question remains: does premium gas have ethanol? The answer isn’t as straightforward as you might think. While premium fuel is known for its higher octane rating, its ethanol content varies depending on where you live and which gas station you visit. This comprehensive guide will explain everything you need to know about ethanol in premium gasoline, helping you make informed decisions at the pump.
What Is Ethanol and Why Is It in Your Gasoline?
Ethanol is primarily produced from corn in the United States
Ethanol is a renewable biofuel made primarily from corn and other plant materials. It’s a form of alcohol that burns cleaner than pure gasoline and helps reduce harmful emissions. The most common ethanol-gasoline blend in the United States is E10, which contains 10% ethanol and 90% gasoline.
The federal government began promoting ethanol in gasoline through the Renewable Fuel Standard program, which requires transportation fuel sold in the United States to contain a minimum volume of renewable fuels. This program aims to reduce greenhouse gas emissions and decrease dependence on imported oil.
“More than 98% of U.S. gasoline contains ethanol to oxygenate the fuel. Typically, gasoline contains E10 (10% ethanol, 90% gasoline), which reduces air pollution.”
Ethanol serves several purposes in gasoline:
- Acts as an oxygenate to help gasoline burn more completely
- Reduces carbon monoxide and other toxic emissions
- Boosts octane rating, which helps prevent engine knocking
- Extends the fuel supply as a renewable resource
Does Premium Gas Contain Ethanol?
The short answer is yes—most premium gasoline in the United States does contain ethanol, typically in the same 10% concentration (E10) as regular and mid-grade gasoline. This surprises many consumers who assume that paying more for premium fuel means getting ethanol-free gas.
Premium Gas Ethanol Content by Octane Rating
| Octane Rating | Common Name | Typical Ethanol Content | Availability |
| 87 | Regular | 10% (E10) | Nationwide |
| 89-90 | Mid-grade | 10% (E10) | Nationwide |
| 91-93 | Premium | 5-10% (E5-E10) | Nationwide |
| 91-93 | Ethanol-free Premium | 0% (E0) | Limited locations |
Contrary to popular belief, refineries often use ethanol to boost the octane rating of premium gasoline. Ethanol has a higher octane rating (around 113) than pure gasoline components, making it a cost-effective way for fuel producers to achieve the 91-93 octane levels required for premium fuel.
Find Ethanol-Free Gas Near You
Looking for ethanol-free premium gas? Use our station finder tool to locate ethanol-free fuel options in your area.
Regional Variations in Premium Gas Ethanol Content
Ethanol requirements in premium gasoline vary significantly by state and region. While federal regulations establish baseline requirements, states have some flexibility in implementing their own fuel standards.
States with Ethanol-Free Premium Gas Options
Some states have specific exemptions that allow for the sale of ethanol-free premium gasoline. Missouri and Montana are notable examples where state regulations explicitly permit ethanol-free premium options. In these states, you’re more likely to find true ethanol-free premium gas at select stations.
States More Likely to Have Ethanol-Free Premium
- Missouri
- Montana
- Minnesota (some areas)
- Wisconsin (some areas)
- Alabama
- Arkansas
States Less Likely to Have Ethanol-Free Premium
- California
- Oregon
- Washington
- New York
- Illinois
- Ohio
Some states have adopted Low Carbon Fuel Standards (LCFS) that encourage higher ethanol blends to reduce carbon emissions. California, Oregon, and Washington have implemented such standards, making ethanol-free premium gas particularly rare in these regions.
Important Note: Even in states where ethanol-free premium is permitted, availability varies by individual gas station. Many major chains still use ethanol in all their fuel grades, while smaller, independent stations are more likely to offer ethanol-free options.
Premium vs. Regular: Comparing Ethanol Content and Performance
Many consumers assume that premium gasoline contains less ethanol than regular gas, but this isn’t necessarily true. In most cases, premium, mid-grade, and regular gasoline all contain the same percentage of ethanol—typically 10% (E10).
Performance Comparison
The primary difference between premium and regular gas is the octane rating, not the ethanol content. Premium gas typically has an octane rating of 91-93, while regular gas has an octane rating of 87. This higher octane helps prevent engine knocking in high-performance engines.
Pros of Premium Gas
- Higher octane prevents knocking in engines designed for premium fuel
- May include better detergent additives in some brands
- Can improve performance in high-compression engines
- Required for many luxury and high-performance vehicles
Cons of Premium Gas
- Higher cost with minimal benefit for regular engines
- Usually contains the same amount of ethanol as regular gas
- No significant improvement in fuel economy for most vehicles
- Does not extend engine life in engines designed for regular gas
It’s important to note that using premium gas in a vehicle designed for regular gas typically provides no benefit. The higher octane rating only matters for engines specifically designed to take advantage of it. If your vehicle’s manual recommends regular gas, using premium won’t improve performance or fuel economy.
“There is a difference between states on whether premium gas specifically has ethanol in it or not. Or, more correctly, whether it’s required to have it in it. Two states in the Union, Missouri and Montana, have specific exemption to allow ethanol-free premium gasoline.”
Common Myths About Premium Gas and Ethanol
Myth: Premium gas is always ethanol-free
Fact: In most states and at most gas stations, premium gasoline contains the same amount of ethanol (typically 10%) as regular and mid-grade gas. Only specific stations in certain states offer truly ethanol-free premium options.
Myth: Premium gas gives better mileage due to less ethanol
Fact: Since premium gas usually contains the same amount of ethanol as regular gas, any mileage difference is not due to ethanol content. Ethanol contains about 30% less energy per gallon than gasoline, but this affects all fuel grades equally if they contain the same percentage of ethanol.
Myth: Premium gas is better for all engines
Fact: Premium gas only benefits engines specifically designed for it. Using premium gas in an engine designed for regular gas provides no performance, efficiency, or longevity benefits and is simply a waste of money.
Myth: Premium gas with ethanol damages engines
Fact: Modern vehicles (built after 2001) are designed to run on E10 (10% ethanol) without issues. Problems typically only arise with higher ethanol blends (like E15 or E85) in vehicles not designed for them, or in older vehicles with rubber components that can be degraded by ethanol.
How to Find Ethanol-Free Premium Gas
If you’re specifically looking for ethanol-free premium gasoline, here are some strategies to help you find it:
- Check fuel labels at the pump – Federal regulations require that fuel containing more than 10% ethanol must be labeled. Some stations also label ethanol-free options.
- Use online ethanol-free gas finders – Websites and apps like Pure-Gas.org maintain databases of stations offering ethanol-free fuel.
- Look for marinas and small airports – These often sell ethanol-free gas for boats and small aircraft, and sometimes allow public purchases.
- Try smaller, independent stations – They’re more likely to offer specialty fuels like ethanol-free premium than major chains.
- Check rural areas – Stations in farming communities often offer ethanol-free options for agricultural equipment.
When you do find ethanol-free premium gas, expect to pay a premium price—often 30-80 cents more per gallon than regular premium gasoline. This price difference reflects both the higher production cost and the specialty nature of the product.
Tip: Always check your vehicle’s owner manual before deciding on a fuel type. Some newer vehicles are optimized for specific ethanol blends, and using ethanol-free gas may not provide any benefit.
Effects of Ethanol in Premium Gas on Your Vehicle
Understanding how ethanol in premium gas affects your vehicle can help you make informed fueling decisions:
Short-Term Effects
- Slightly reduced fuel economy – Ethanol contains less energy per gallon than pure gasoline, resulting in slightly lower mileage (typically 1-3%).
- Potential cold-start issues – In very cold weather, ethanol-blended fuels may cause harder starting in some vehicles.
- Water absorption – Ethanol attracts and absorbs water from the atmosphere, which can cause problems if fuel sits for extended periods.
Long-Term Effects
- Potential fuel system degradation – In older vehicles (pre-2001), ethanol may degrade certain rubber and plastic components not designed for it.
- Cleaner combustion – Ethanol burns cleaner than pure gasoline, potentially reducing carbon deposits in the engine over time.
- Fuel system cleaning – Ethanol has solvent properties that can help clean fuel system components, though it may also loosen existing deposits.
For most modern vehicles, the 10% ethanol content in premium gas poses no significant problems. Manufacturers have designed fuel systems to handle this level of ethanol. However, for certain applications—classic cars, boats, small engines, and seasonal equipment—ethanol-free gas may be preferable to avoid potential issues with fuel system components and fuel stability during storage.
Making the Right Choice at the Pump
When it comes to premium gas and ethanol content, there’s no one-size-fits-all answer. The best choice depends on your specific vehicle, how you use it, and your local fuel options.
For most modern vehicles, standard premium gas with 10% ethanol is perfectly acceptable and will provide the high-octane performance needed for engines designed for premium fuel. If your vehicle specifically requires premium gas, using regular gas could cause knocking and potential engine damage.
On the other hand, if you’re fueling classic cars, boats, or small engines—or if you plan to store fuel for extended periods—seeking out ethanol-free premium gas may be worth the extra cost and effort.
Remember that the primary benefit of premium gas is its higher octane rating, not its ethanol content. If your vehicle is designed for regular gas, premium won’t provide any significant benefits regardless of its ethanol content.
