What Brand Of Gas Does Costco Sell And Is It High-Quality?

Costco sells a huge quantity of gas each year to its members, who have all paid a membership fee for the privilege of purchasing gasoline at prices which are usually much lower than those found at other fuel retailers. The brand of gasoline sold at Costco gas stations is Kirkland Signature, which is Costco's in-house brand. 

The amount of gasoline that people worldwide buy from Costco turns out to be a pretty staggering amount in terms of dollars. In fiscal year 2024, Costco operated 719 gas stations worldwide, an increase of 40% over the number of stations it had as recently as 2016. These 719 stations sold an incredible $30 billion dollars worth of gasoline in that 12-month period. This $30 billion number reflects an almost two-fold increase from 2019, when Costco had $16.4 billion in gas revenue. 

Gasoline sales represented 12% of Costco's total net sales in fiscal year 2024, which equates to about one-eighth of Costco's overall sales for the year. That is a lot of gasoline. In addition to all of that gasoline that Costco sells, the retailer also sells name-brand tires, Kirkland brand motor oil (along with other brands), and a variety of other products for your car and truck.  

The Costco gas sold at most Costco gas stations is actually of very high quality. The proof of this is that Costco's gas in its major markets meets TOP TIER™ performance standards. These standards have been developed by a group of automakers that include Audi, BMW, Ford, General Motors, Honda, Mercedes-Benz, Stellantis, Toyota, and Volkswagen. TOP TIER™ standards require higher levels of detergent additives than ordinary gasoline. These automakers recommend the regular use of TOP TIER™ gasoline to keep your engine operating properly and to minimize the buildup of carbon deposits within your engine. These carbon deposits can cause problems such as stalling, difficult starting, hesitation, decreased fuel economy, and higher emissions. 

Costco states on their website that "Kirkland Signature™ Gasoline contains five times the EPA detergent requirement in both regular unleaded and premium grades, and is formulated to clean your engine and help your vehicle run like new." In fact, Costco's gasoline meets these TOP TIER™ performance standards in five different markets where Costco gas is sold. This includes the United States, Canada, Puerto Rico, Mexico, and Japan. These rigorous performance standards are verified through the testing of engines at independent testing laboratories.

There are some other markets in which Costco operates self-service gas stations, but the gasoline sold in these locations does not meet TOP TIER™ performance standards. These stations are located in Australia, Iceland, Spain, Taiwan, and the United Kingdom.