Both Sam’s Club and Costco have reliable gas quality. While Sam’s Club gas comes with the company’s Satisfaction Guarantee, Costco’s gas is TOP TIER certified, meaning that it has more deposit control additives than the EPA requires.
Sam’s Club Gas Quality
Sam’s Club operates independent, unbranded gas stations, meaning it doesn’t source its fuel from a single oil company.
The company assures the quality of its gasoline with the Sam’s Club Satisfaction Guarantee.
However, Sam’s Club gasoline is not licensed as TOP TIER.
Walmart operates Sam’s Club; and while it doesn’t disclose its fuel suppliers, Walmart cut ties with its long-time gasoline provider, Murphy USA, in 2016.
Neither Walmart nor Sam’s Club disclose much information about maintenance at their gas stations, but the companies are required to follow the minimum guidelines set by the Environmental Protection Agency (EPA), the National Fire Protection Association (NFPA), state governments, and other regulatory bodies.
How to Buy Gas at Sam’s Club
You must have a Sam’s Club membership to purchase fuel at most of the retailer’s gas stations.
However, some Sam’s Club stores co-located with Walmart allow non-members to buy gas.
- Cost of membership: $45 per year for a standard personal or business membership; $100 per year for a “Sam’s Plus” membership
- Payment methods for gas: Most major credit cards (including the Walmart Rewards Card and Capital One Walmart Rewards Card), cash, checks, debit cards, and Walmart and Sam’s Club gift cards
Costco Gas Quality
Like Sam’s Club, Costco operates unbranded gas stations, and while the company doesn’t disclose much information about its fuel suppliers, its website states that its fuel comes from the same major refineries that supply all the gas stations in a given area.
The company follows strict protocols to ensure its gasoline is clean. Costco is a licensed TOP TIER brand that sells its own formulation of Kirkland Signature Gasoline, which contains five times the deposit control additives required by the EPA.
How to Buy Gas at Costco
If you don’t have a Costco membership or Shop Card, you’ll need to get gas elsewhere; Costco doesn’t offer temporary passes.
- Cost of membership: $60 per year for a basic “Gold Star” or business membership; $120 per year for an “Executive” membership, which offers a 2% cash-back reward (including gas purchases)
- Payment methods for gas: Visa credit cards, most pin-based debit cards, and Costco Shop Cards
TOP TIER Gasoline Standards
In 1995, the EPA set a standard for the lowest additive concentration allowed in commercial gasoline.
However, in 2004, a group of automakers created TOP TIER gas, which includes a specific level and formulation of deposit control additives that exceed EPA standards.
Engine carbon deposits are reduced by 19 times with TOP TIER gas. As a result, drivers may experience better drivability, better fuel economy, and fewer emissions.
TOP TIER gas costs an average of three cents more per gallon than other brands, but it has become the standard for high-quality gasoline.