Email your questions about Kirkland Signature™ Gasoline to: KSGasoline@costco.com
Since 1995, all gasoline sold in the U.S. must include an EPA-approved deposit control additive. Commonly called detergents, all Costco gas has always contained these additives. Costco gas stations are well maintained and our fuel has always been 100% guaranteed.
Increasing Federal emissions and mileage requirements have led to improved and more complicated engine designs. These improvements make many engines more sensitive to carbon deposits on intake valves and clogged fuel injectors. In the worst cases, dirty engines can sometimes trigger a "check engine" dashboard warning light. Many of the latest model vehicles perform better using fuel that contains more than the minimum EPA detergent requirement. In fact, several automobile manufacturers recommend the use of TOP TIER™ gasoline to maintain optimal performance.
As our valued member, you expect Costco to always offer the finest quality products at the best possible price. Gasoline is no exception. Costco has closely studied fuel additives and engine deposits, and conducted extensive engine tests at nationally-recognized laboratories. As a result, we decided to increase the detergent additives in our fuel to provide a better value to our members. As of March 2014 Costco is listed as a TOP TIER™ gasoline retailer. Find out more at toptiergas.com/retailers.html.
Kirkland Signature™ Gasoline contains five times the EPA detergent requirement in both regular unleaded and premium grades. Kirkland Signature™ Gasoline helps remove any existing deposits and keeps your engine clean.
CLEANING YOUR ENGINE:
Improves performance - everyone wants their car to start promptly, accelerate quickly, and idle smoothly. A clean engine will most likely run like new and testing shows that Kirkland Signature Gasoline cleans up dirty engines and keeps them clean.
Restores fuel economy - cleaning up existing deposits and fuel injectors can restore mileage lost to dirty engines. Regular use of Kirkland Signature™ Gasoline promotes consistently clean engines, helping to restore an engine's intended fuel economy.
Reduces emissions - removing deposits allows the engine's sophisticated emissions controls to work as designed, helping to reduce tailpipe pollution caused by intake valve deposits and plugged fuel injectors.
Protects fuel injectors & intake valves - deposit control additives prevent new deposits from accumulating by forming a protective molecular layer on certain critical engine parts. This increases vehicle reliability, lowers maintenance, and helps extend engine performance.
Intake Valve Test Results
Intake valves tested with EPA minimum-standard gasoline (top) and Kirkland Signature™ Gasoline (bottom).