You probably know that Costco members pay less for gas. But are their gases better or worse than their competitors? In this article, we’ll look at Costco’s natural gas quality in 2025 and discuss what makes it competitive. We’ll also look at the applicable gasoline standards, and if you’re not convinced, we’ll also discuss some ways to improve the quality of Costco gasoline.
Cheap gas, yes. But what about Costco gas quality?
According to Consumer Reports.com, warehouse gas prices are typically 5 to 25 cents cheaper per gallon ( here ). However, for most consumers, lower prices are often seen as a signal of lower quality. That may raise questions about the quality of the gasoline Costco sells at only 580 U.S. stations.
Gas at Costco is cheap for two reasons. First, Costco does a better job than its competitors at controlling prices in its gasoline business. Generally speaking, Costco’s SG&A (selling, general and administrative) costs are lower than Walmart and Target ( here ). This means they can afford to keep prices low.
Secondly, Costco’s business philosophy is to provide high-quality goods at competitive prices. So, this means that in order to sustain business growth, Costco needs to sell gas at a lower price than its competitors to attract people into their warehouse stores. So they’re sacrificing some profits from their gasoline business to get more people into their warehouses.
But what is the quality of Costco’s gas?
gas quality standards
First, it’s worth noting that the Environmental Protection Agency (EPA) sets strict standards for all gasoline sold in the United States. All gasolines are essentially the same when it comes to octane rating and other specific gasoline characteristics. The difference between the fuel you buy at a branded gas station depends on the detergents added to the gasoline.
Gasoline is basically an impure substance derived from an impure base oil, crude oil. This means that it is messy from a molecular chemistry perspective. Also, some gasoline can leave gunk around the injectors and intake valves. This can increase or decrease engine efficiency. To alleviate this, fuel manufacturers add detergents or chemicals to help break down the semisolids in gasoline. Detergents are typically amine-, alcohol- (ethanol), sulfur- or zinc-based chemicals that contain polar and non-polar groups in their molecular structure.
Even for detergents, the government sets standards. The federal government has required that all gasoline sold in the United States contain certain detergent additives since 1995. These additives are approved by the EPA, and the amount of detergent that must be added to prevent deposits in a vehicle’s engine is regulated. Costco gas ticks all these boxes, despite being much cheaper than surrounding gas stations. So just because you save money, doesn’t mean they save money or circumvent any regulations.
Is Costco Gas as good as the competition?
Therefore, Costco meets the minimum requirements set by the EPA, but also meets the more stringent requirements set by the automotive manufacturing industry.
Many automakers believe the U.S. government’s additive requirements are not high enough for many vehicles. As a result, they set “top” standards. To qualify for the “Premium” designation, the fuel sold at gas stations must meet additive requirements that are higher than those required by the U.S. government. Costco fuel meets this top standard.
Therefore, Costco gasoline is effectively the same as other major brands of gasoline because it meets EPA and industry standards. When filling up your vehicle at Costco, you shouldn’t notice any difference from any other brand of vehicle. The only difference you should notice is that it’s less of a hit on your wallet.
Additionally, Costco has strict filtration requirements for its fuel, according to its website:
Station maintenance Good gas station operation and maintenance means the fuel is filtered and contaminants such as sediment and water do not enter our members’ vehicles. Costco gas stations are well maintained by our capable attendants, so you can be confident that the fuel going into your vehicle is clean.
- Costco uses fuel filters to capture particles or debris larger than 10 microns in diameter. By comparison, the average thickness of human hair is seventy microns.
- Our attendants frequently check the nozzle flow to ensure our filters are fresh. When the flow rate drops below 8 gallons per minute, we need to replace the filter.
- Costco uses ethanol-compatible filters designed to capture sediment, water, or a phase-separated ethanol and water mixture.
- Costco’s electronic sensors continuously monitor the water levels in our underground storage tanks.
- We perform physical inspections of storage tanks and collect chemical samples at least weekly to confirm the absence of contamination.
Source: Costco.com.
Get better gas quality and save money
If you’re not sure whether Costco gasoline is as good as other major brands of gasoline, try using a “gasoline hack” to save money. In most parts of the country, you can fill up your tank at a Costco gas station and add a high-quality injector cleaner. Chevron sells a quality injector cleaner, as does STP. You can buy Chevron’s injector cleaner on Amazon, click here. You can also click on the photo below.
If you add this injector cleaner as recommended, you’ll still pay less for Costco gasoline and injector cleaner than you would for gasoline separately at a major brand gas station.
This is more of a reassuring improvement, though. Most mechanics will tell you that injector cleaner really doesn’t do much, so maybe just enjoy the savings of an annual membership.
Finally, there is nothing to suggest that Costco brand fuel is inferior to any other brand of gasoline. Don’t let price alone stop you from filling up there.
from the web
If you’re interested in some interesting gasoline reads, check out this story about a man who figured out how to turn off gas station ads. And, here’s the story of a guy who made $900 using the cash back Gas app Upside. Best of all, he donated $900 to buy gas for some nurses. The story ends here.
Read more savings tips:
Costco Gas Calculator: Will I Save Money with a Membership if I Only Purchase Gas?
Getting Costco Gas? Don’t forget to check their holiday schedule
Open early and close late – Costco gas station opening hours
Is it worth joining a Costco membership when you live alone?
10 fuel-saving misunderstandings that actually cost you money
Do you fill up at a Costco gas station? What are your thoughts on gas quality?
