Costco Gas Prices in Phoenix, AZ

Costco does not sell a refiner’s brand. Every pump in Phoenix dispenses Costco’s own Kirkland Signature fuel, bought from major refiners and distributors in the region and finished with Costco’s additive package.

Kirkland Signature gasoline is licensed TOP TIER, the detergent standard set by automakers including GM, Ford, Toyota, Honda and BMW. Costco puts its detergent level at about five times the EPA minimum, which is what keeps intake valves and fuel injectors clear of carbon deposits. Costco’s gasoline also contains friction modifiers that it says reduce engine wear.

In short, the low price is not a lower grade. The saving comes from Costco running its gas as a membership perk on thin margins, not from the fuel.

Bring your card. The pump asks for an active Costco membership card before it starts, at all 5 gas stations in Phoenix. Without a membership, a Costco Shop Card loaded with credit works the same way.

Pay by card. The pumps take Visa, most debit cards and the Costco Shop Card. There is no cash, and a card hold of up to $150 can show until the fill posts.

Check the price first. Each station sets its own price, usually once a day, so two Costco stations in Phoenix can differ. Today the regular average here is $4.705. The prices on this page are collected once daily and can lag a same-day change at the pump.

Go early or late. Lines are longest on weekend afternoons and weekday evenings. The first pumps here open at 6 a.m. on weekdays.