Is Costco Gas Good For Your Engine?

If you’re a regular Costco Gas customer, you might already be familiar with the quality of Costco’s fuel. But if you’re new to this fuel supplier or if you’re considering buying a Costco membership to get access to their low gas prices, then you’re probably wondering about the quality of Costco gas.

Keep reading to learn everything about the quality of Costco gas!

Costco gas good

Is Costco Gas Good For Your Engine?

Despite being so much more affordable than gas from other suppliers, Costco’s Kirkland Signature™ fuel is TOP TIER™ and even exceeds EPA standards. This gasoline is formulated to clean your engine, help your car run like new, and maximize fuel economy.

You can read all about Costco’s fuel promise here.

What Are The Types Of Gas Sold At Costco?

First off, Costco Gas stations keep their fuel offerings pretty simple. All Costco Gas locations offer regular and premium fuel, while some locations also offer diesel. All of the gas supplied at Costco Gas stations is Kirkland Signature™ gasoline.

According to Costco’s gasoline Q&A, the average octane rating of their regular fuel is 87 while the average rating for premium is 91. These numbers may vary by state.

How Much Is Gas At Costco?

Gasoline at Costco is typically less expensive than from other places, but the exact amount for a gallon of gas will differ based on fuel type, time of year, location, etc.

First off, in order to buy gas from Costco, you’ll need a Costco membership. The starting cost for a membership is $60 per year, with higher level memberships coming in at $120 per year. Once you have your membership card in hand, you can access the low gas prices at Costco.

To find out how much you can expect to pay for a gallon of gas at Costco today, use the “Find a Warehouse” tool on the chain’s website. In the search bar, type in your zip code or city and state, then select the store location you wish to visit from the list below. Beneath the store information, you’ll see a gas pump icon. All you have to do is click on this icon, and the store hours will appear with a listing of the gas prices below.

Here is a screenshot showing what it will look like when you search for your local Costco’s gas price.

Costco gas price location

Here, you can see that a gallon of regular gas at the Costco location in Issaquah, Washington, is currently $4.49. This is about $0.25 cheaper than the current market average for the region.

In other places, Costco gas might be as much as $1.00 cheaper than fuel from other locations. The best way to find out is to search ahead and compare prices between the locations nearest you.

Why Is Costco Gas So Cheap?

The reasons behind Costco’s low gas prices are pretty simple. And it isn’t just some scam based on low-quality gas, thankfully!

Mainly, everything is cheaper at Costco because the company gathers membership fees from all of its shoppers. In fact, memberships make up 75% of the company’s profits. So, with all that money coming in up front, Costco can afford to charge a little less at the pump.

The other reason why Costco can offer rock-bottom prices on their gas is because most shoppers aren’t just buying gas. On top of being members, people filling up at the Costco pump are likely to do a bit of shopping at the warehouse as well. Costco entices customers to their locations by offering affordable fuel and trusting that their customers will visit the store to load up on other things as well, like bulk items and home goods. It’s all about customer loyalty with this chain! And it’s a formula proven to work, just like their fuel!

Benefits Of Getting Gas At Costco

There are so many benefits to getting gas at Costco!

Here is a list of just a few:

  • Low prices
  • High-quality fuel with top tier standards
  • Check and compare prices for any location online before you go (check on the website or download the Costco app)
  • Safety-certified attendants onsite

For more thoughts on why you should buy gas at Costco, visit Costco’s 7 Reasons to Fuel Up at Costco Gas Stations.


Does Costco Gas Contain Ethanol?

Because Costco gasoline is a high-quality fuel type, it thankfully does not contain any ethanol.

Where Does Costco Get Their Gas?

All of the gasoline sold at Costco Gas stations is Kirkland Signature™ gasoline, and Costco buys its gasoline from major and local refineries. Essentially, there is no big difference between Costco’s gasoline and gasoline from other major suppliers like Shell or Chevron. All of the fuel comes from the same source and it is all TOP TIER™ rated and approved by the highest EPA standards.

Is Costco Gas Considered Top Tier?

TOP TIER™ gasoline is any gasoline that contains a higher amount of additive detergents than EPA standards require. These detergents help clean your engine as your car runs and improve the overall performance and lifespan of your engine.

Costco’s Kirkland Signature™ gasoline qualifies as TOP TIER™.

Should You Buy Costco Gas?

Honestly, we think you should! The benefits of buying gas at Costco are many. Costco Gas customers get access to…

  • Lower-than-average fuel prices
  • On-site safety attendants
  • Ease of checking and comparing prices by location online before you head out
  • High-quality fuel with top tier standards

But we don’t want you to feel misled, so we’ll also give you an overview of the downsides of buying gas at Costco.

Downsides Of Costco Gas

While the perks are abundant, there are admittedly some downsides to buying gas at Costco as well. 

These downsides include:

  • Long lines
  • Membership is required
  • Locations and hours are limited compared to other fuel suppliers
  • Visa credit cards or debit cards are the only accepted form of payment (cash is not accepted)


Do Costco members get discounts on gas?

No. Costco members do not receive discounts of any kind. However, Costco gas is already priced lower than what shoppers would pay elsewhere, so in a sense, members do get access to fuel discounts by paying for a membership.

Can you buy gas at Costco without a membership?

No. Without a membership or a Costco Shop Card (gift card), you will not be able to purchase fuel at a Costco gas station.

How Does Costco know if you’re a member?

Most shoppers carry their Costco member card in their wallet to present whenever they shop at a Costco Warehouse or fill up at a Costco gas pump. But you can also memorize your member number or simply provide your ID to prove your membership.

If you forget your member card and member number at the pump, you will have to go inside the warehouse and visit the guest services desk to receive a temporary card.

What is the octane rating for Costco premium gas?

Although it may vary slightly by state, Costco’s premium gas is typically rated at around 91 octane.

Can you fill gas cans at Costco?

Yes. Approved fuel containers can be filled at Costco gas stations, but they must be removed from your vehicle and placed on flat ground during filling.

Does Costco gas ruin your engine?

Definitely not! Costco gas is very high quality and is comparable to gas from other reliable suppliers like Shell and Chevron.

Is Costco gas open 24/7?

No. Costco Gas hours vary by location, but most stations open between 5 AM and 8 PM and close between 8 PM and 10 PM. Use the store locator tool to look up the hours of your local Costco Gas station.


Isn’t Costco great? Low prices, amazing customer service, and top tier gasoline? We’re sold! Time to go out and get your Costco membership so that you can start filling up at the Costco pump ASAP. Happy driving!

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