Does Costco Have Ethanol-Free Gas? The Definitive Answer and Expert Guide

Let’s cut to the chase: Costco does not generally offer ethanol-free gasoline at its stations. The vast majority of Costco gas stations, like most major retailers, sell gasoline that contains up to 10% ethanol (E10). This is mandated in many areas due to environmental regulations and the Renewable Fuel Standard. However, this doesn’t mean the story ends there. There’s a lot more to unpack about ethanol, gasoline quality at Costco, and alternative options for those seeking ethanol-free fuel.

Understanding Ethanol and Its Role in Gasoline

Before diving deeper into Costco’s fuel offerings, it’s crucial to understand why ethanol is added to gasoline in the first place. Ethanol is an alcohol produced primarily from corn in the United States. It’s blended with gasoline for several reasons, including:

• Increasing Octane: Ethanol has a high octane rating, which can boost the octane level of the final gasoline product, potentially improving engine performance.
• Reducing Emissions: Ethanol is considered a renewable fuel source, and its use can slightly reduce greenhouse gas emissions compared to gasoline alone.
• Oxygenating Fuel: Ethanol adds oxygen to gasoline, which can help improve combustion and reduce carbon monoxide emissions.

While ethanol offers some benefits, it also has drawbacks.

The Downsides of Ethanol in Gasoline

• Reduced Fuel Economy: Ethanol contains less energy per gallon than gasoline, which can lead to a slight decrease in fuel economy, typically around 3-4%.
• Water Absorption: Ethanol is hygroscopic, meaning it attracts and absorbs water. This can lead to phase separation, where the ethanol and water separate from the gasoline, potentially damaging fuel systems, especially in older vehicles and small engines.
• Corrosion: Ethanol can be corrosive to certain materials, particularly rubber and plastic components found in older fuel systems.

Costco’s Gasoline and Kirkland Signature Fuel

Costco’s gasoline, sold under the Kirkland Signature Fuel brand, is known for its quality and competitive pricing. While it typically contains up to 10% ethanol, Costco emphasizes that its gasoline meets or exceeds all industry standards and is formulated to provide optimal performance and fuel efficiency for most vehicles.

Top Tier Gasoline and Costco’s Commitment

Costco gasoline is certified as Top Tier gasoline. This means it contains a higher level of detergents and additives than the minimum required by the EPA. These additives help keep engine components clean, prevent deposit buildup, and maintain optimal engine performance. This is a significant advantage, even with the presence of ethanol. Costco’s dedication to quality gives customers peace of mind knowing that while the gas has ethanol, it’s formulated to mitigate most of the adverse impacts.

Why is Ethanol-Free Gasoline Hard to Find?

The widespread adoption of ethanol-blended gasoline is largely due to government mandates and incentives aimed at promoting renewable fuels. As a result, finding ethanol-free gasoline has become increasingly difficult, particularly in urban areas. It’s generally more common in:

• Rural Areas: Some rural gas stations still offer ethanol-free gasoline, particularly in areas where older vehicles and small engines are prevalent.
• Marinas: Ethanol-free gasoline is often available at marinas, as ethanol can be particularly damaging to boat engines.
• Specialty Fuel Suppliers: Some specialty fuel suppliers cater to enthusiasts and professionals who require ethanol-free gasoline for specific applications, such as racing or aviation.

Alternatives for Those Seeking Ethanol-Free Fuel

If you’re looking for ethanol-free gasoline, here are some strategies and alternatives:

• Use a Fuel Finder: Websites and apps like Pure-Gas.org and E85prices.com can help you locate gas stations that sell ethanol-free gasoline in your area. Be sure to call and confirm availability as inventories can change.
• Check Local Marinas: As mentioned earlier, marinas often carry ethanol-free gasoline for boat engines.
• Consider Racing Fuel: While expensive, racing fuel is typically ethanol-free and has a high octane rating. However, it’s crucial to ensure that the fuel is compatible with your vehicle’s engine.
• Ethanol Shield Additives: If using ethanol-blended gasoline, consider using a fuel additive designed to protect fuel systems from the harmful effects of ethanol. These additives can help prevent corrosion, phase separation, and other issues.
• Use Premium Gas: Some brands’ premium gasoline may contain lower percentages of ethanol than regular gas. Check with the fuel supplier in your area to see if this is an option.

Frequently Asked Questions (FAQs) About Costco Gasoline and Ethanol

Here are some frequently asked questions about Costco gasoline and ethanol:

1. Is all Costco gasoline E10?

Generally, yes. The vast majority of Costco gas stations sell gasoline containing up to 10% ethanol (E10). While specific formulations may vary slightly by region, expect to find E10 gasoline at most Costco locations.

2. Does Costco offer premium gasoline without ethanol?

While it varies by location, it is highly unlikely. While premium gasoline may offer higher octane, it generally still contains up to 10% ethanol.

3. Why does Costco use ethanol in its gasoline?

Costco uses ethanol in its gasoline primarily to comply with federal and state regulations, including the Renewable Fuel Standard. Additionally, ethanol can increase octane and reduce emissions.

4. Will using E10 gasoline from Costco damage my car?

For most modern vehicles, using E10 gasoline is perfectly safe. Vehicles manufactured in recent decades are designed to withstand the effects of ethanol. However, older vehicles (typically pre-1990s) may experience issues.

5. What are the symptoms of ethanol damage in older vehicles?

Symptoms of ethanol damage can include fuel system corrosion, rubber and plastic component degradation, fuel line leaks, and engine performance issues.

6. How can I protect my older vehicle from ethanol damage when using Costco gas?

Use a fuel additive specifically designed to protect against ethanol. These additives can help prevent corrosion, stabilize the fuel, and protect rubber and plastic components.

7. Does Costco’s Kirkland Signature Fuel contain detergents to protect my engine?

Yes, Kirkland Signature Fuel is certified as Top Tier gasoline, meaning it contains a higher level of detergents than the minimum required by the EPA. These detergents help keep engine components clean.

8. Is it safe to use Costco gasoline in my small engine equipment (lawnmowers, generators, etc.)?

It’s generally not recommended to use E10 gasoline in small engines, as ethanol can cause significant damage. Always consult your equipment’s owner’s manual for specific fuel recommendations. If ethanol-free gasoline is unavailable, use a fuel stabilizer specifically designed for small engines to mitigate the effects of ethanol.

9. Will using E10 gasoline from Costco reduce my fuel economy?

Yes, ethanol contains less energy per gallon than gasoline, which can lead to a slight decrease in fuel economy, typically around 3-4%.

10. How can I find out the exact ethanol content of the gasoline at my local Costco?

While Costco doesn’t typically publish the exact ethanol content, you can often find a sticker on the pump indicating that the gasoline contains “up to 10% ethanol.” The actual percentage may vary slightly.

11. Does Costco offer any alternative fuels besides gasoline?

Some Costco locations may offer diesel fuel. However, Costco does not currently offer alternative fuels like E85 or biodiesel at most of its stations.

12. If I’m concerned about ethanol, is it worth paying extra for premium gasoline at Costco?

The primary benefit of premium gasoline is its higher octane rating. If your vehicle doesn’t require premium gasoline, there’s generally no need to pay extra. Premium gasoline at Costco will still likely contain up to 10% ethanol. The exception would be if a particular brand’s premium fuel contains no ethanol at certain stations. However, that would not be the norm at a Costco station.

In conclusion, while Costco doesn’t typically offer ethanol-free gasoline, its Kirkland Signature Fuel is a high-quality product that meets industry standards and contains detergents to protect your engine. For those seeking ethanol-free fuel, exploring alternative options and using appropriate fuel additives is crucial.