How Much Can You Really Save With Costco Gas Prices?

If you haven’t bought Costco gas with your membership card yet, you’re missing out on some easy savings. But how much can you really save with the price of gas at Costco? Is a Costco membership worth it just for the gas savings alone?

I crunched a few numbers and found that Costco gas prices are about $0.11 cheaper per gallon than other nearby gas stations. While those savings don't sound like much (about $1.50 saved per fill-up for my 12-gallon tank), they can really add up over the course of a year. And if you frequent the gas station a lot, your Costco gas savings could even cover the cost of a membership.

That's just the beginning of what I found out when I started digging into Costco gas. Like, did you know there's a cheapest day to buy gas at Costco (and it's not the same as the best time to shop at Costco)? And they even have a Costco-approved method for getting gas without a Costco membership.

For more smart shopping tips and savings hacks, download the KCL app or text HACKS to 57299.

How much cheaper is Costco gas?

The price of gas at Costco will depend on where you live and the current cost of a barrel of gas. But those factors aside — I compared the gas prices in six cities around the U.S. and found that Costco was the overall cheapest gas station about 67% of the time. For regular unleaded gas, Costco gas offered average savings of $0.11 per gallon compared to other nearby gas stations.

And the savings were even higher with premium gas. Based on my research, I found that Costco premium gas is usually $0.22 - $0.51 cheaper per gallon than other nearby gas stations. And for the gas stations I compared, Costco had the cheapest premium gas 100% of the time.

But how (and why) is Costco gas cheaper than competitors? A Fuel Insights report from GasBuddy explains it like this:

"The Big Box clubs might sell gasoline at or near cost, hoping to increase the frequency of consumer visits and lure customers inside warehouses."

What's the cheapest day to get gas at Costco?

Based on the data in another report from GasBuddy, the cheapest day to buy gas is typically Monday. And since Costco tends to keep their gas prices pretty competitive, you can expect this pattern to hold at Costco, too.

After Monday, the next-cheapest day to buy gas is either Friday or Sunday.

"Though there is variation in daily gas prices across different states, the consensus is that filling up at the beginning or end of the work week, on Monday or Friday, is the best way to save money," said GasBuddy petroleum analyst Patrick De Haan in the 2022 GasBuddy report.

As for the best time to get gas at Costco, stick to the early mornings. Gas prices are usually at their lowest for the day, and the Costco parking lot will be less crowded. Many Costco gas stations open as early as 6 a.m. — a few hours earlier than the warehouse itself.

Editor note: I reached out to GasBuddy on Feb. 14, 2024, to request an updated report on the cheapest day to buy gas. According to Patrick De Haan, they "have not yet updated the study with new numbers."

Is Costco good quality gas?

Costco's Kirkland Signature gas is actually one of the highest quality gasolines you can buy. And I'm not just saying that because I'm a big fan of the Kirkland Signature brand.

Costco gasoline received certification as a "Top Tier" fuel in 2014. Earning that certification means that they must meet strict guidelines that regulate the amount of additives and detergents in their gas. These fuel additives can help clean the injectors in your engine and improve your gas mileage, ultimately saving you money in the long run.

KCL TIP: Besides Kirkland gas at Costco, other popular fuel brands like Chevron, Exxon, Mobil, and Shell have the Top Tier certification. You can find the full list of brands on the Top Tier website.

Is Costco membership worth it just for gas?

Your total yearly gas savings will depend on the size of your gas tank and the current price of gas. But let's just assume that you're saving about $0.11 per gallon of regular unleaded gas at Costco.

Here's how much you'd need to spend to cover the cost of membership:

• For a 12-gallon gas tank, it would take about 45 fill-ups per year to cover the cost of a $60 Gold Star membership. (About one trip to the gas station per week.)

• For a 12-gallon gas tank, it would take about 91 fill-ups per year to cover the cost of a $120 Executive membership. (About two trips to the gas station per week.)

Of course, if your gas tank is larger than 12 gallons, you'd need fewer fill-ups to make a membership worth it. And we're not even considering all the other savings you can rack up with a Costco membership.

One tradeoff is that you won't be able to use popular cash back receipt apps like Upside or GasBuddy with Costco receipts, as their gas stations don't participate.

KCL TIP: If you pay with a Costco Visa credit card, you'll also earn 4% cash back on your annual gas purchases up to a maximum of $7,000. That means you can earn an additional $280 back per year on gas.

How much is Costco Gas?

Besides just visiting the Costco gas pump in person, there are three ways to look up the current Costco gas prices at any location.

1. Costco app: Select the Warehouse icon, then choose a location on the map.

2. Costco.com. Select the Gas Station filter, then choose a location on the map.

3. GasBuddy app: Select Find Gas, then choose a location. Prices are sorted from lowest to highest (and will include Costco, if there's one nearby).

Not every Costco warehouse or Costco Business Center has a gas station, but many do.

Is Costco gas for members only?

Technically, yes. That's because you have to insert a valid Costco membership card at the terminal before you can actually start pumping the gas.

But there is a workaround: just ask a current Costco member to buy you a preloaded Costco Shop Card, then use that gift card to pay at the pump. You'll just need to show your Shop Card to the Costco gas attendant when you arrive so that they can authorize the pump.

KCL TIP: Costco gas stations will only accept Visa credit cards, debit cards, or Costco Shop Cards as payment — no cash.

Sources:

• AAA: "Fuel Quality Fact Sheet"

• Costco: "7 Reasons to Fuel Up at Costco Gas Stations"

• Costco: "Costco Gas Stations: Frequently Asked Questions"

• GasBuddy: "Fuel Insights Methodology: Frequently Asked Questions"

• GasBuddy: "GasBuddy Reveals the Cheapest and Most Expensive Days of the Week to Buy Gas"

• Top Tier: "Top Tier Fuel Stations"