Who Has Better Gas Prices: Costco or Sam's Club?

With inflation still elevated and Americans in the middle of summer travel season, many people are undoubtedly watching gas prices. The average price per gallon of gas is $3.59 right now, which, thankfully, is more than $1 cheaper than at this time last year, according to AAA.

Those looking for even lower gas prices may want to consider a discount club membership at Costco or Sam's Club. Both of which offer significant discounts to the average gas prices.

But which one has better prices? A quick look across five cities shows that it's fairly evenly split across the two companies.

Both stores offer below-average gas prices

I did a snapshot of gas prices across Atlanta, Georgia; Cherry Hill, New Jersey; Sacramento, California; Houston, Texas; and Springfield, Missouri. On the day I checked, gas prices at Sam's Club and Costco were the same at all locations, except in Cherry Hill, where Costco's fuel price was $0.08 cheaper per gallon than a comparable Sam's Club location.

It's difficult to directly compare Sam's Club and Costo gas prices in some cities because their store locations differ. But what's clear is that both clubs offer steep fuel discounts compared to the average. For example, AAA says the average per-gallon gas price in the Atlanta area is $3.39, and I found that both Sam's Club and Costco fuel prices were $0.25 cheaper.

An analyst at GasBuddy, a website that helps people find the best gas prices, said in an interview with Consumer Reports last year that warehouse clubs typically have gas prices that are $0.05 to $0.25 cheaper per gallon than gas stations. They also tend to keep their prices lower longer when fuel prices are on the rise.

And if you're buying Costo gas, you're not skimping on good-quality gas. AAA research shows that Costco's Signature Kirkland Gasoline meets independent TOP TIER standards, which AAA said is proven to be cleaner and help engines perform better.

Should you buy a Costco or Sam's Club membership just for the gas?

If we take the average savings based on the GasBuddy analysis, the median amount that Sam's Club and Costco members save is $0.15 per gallon. Based on the 489 gallons of fuel that Americans buy annually per vehicle, according to the American Petroleum Institute, then Sam's Club and Costco members could save up to about $73 a year. If you fuel up more than one vehicle or burn through more gallons than the average, then your savings will be even higher.

Of course, your savings mileage may vary depending on the price of gas and the discount prices where you live. But even with this conservative estimate, the gas savings easily pays for the cheapest $50 Sam's Club membership or $60 Costco membership. Which means that spending the money for membership could be a smart decision for your personal finances.

And if you're looking to maximize your gas savings, you may want to consider the Costco Anywhere Visa® Card by Citi, which gives 4% cash back on gas purchases up to $7,000, then 1% after that. Similarly, a Sam's Club Mastercard offers 5% cash back on fuel purchases up to $6,000, then 1% after.

So if you're looking for cheap gas, both Sam's Club and Costco memberships will save you money. Sometimes Costco will be cheaper, and sometimes Sam's Club will be. But if you're looking for a good deal on gas prices, you can't go wrong with either.