Costco’s premium gas, available at locations nationwide, has sparked a debate among drivers about its exact octane rating. Is it 91 or 93? And does this difference have any significant impact on their vehicles? As we delve into this topic, we’ll explore how this uncertainty affects fuel choices for everyday and high-performance cars, and the practical considerations like hours and membership that come with buying gas at Costco. We’ll also look at the real-world appeal of Costco’s affordable premium gas, as demonstrated by a driver who joined Costco specifically to fuel his Ferrari.
What is Octane Rating?
Octane rating is a measure of a fuel’s ability to resist ‘knocking’ or ‘pinging’ during combustion in an engine. This knocking is essentially the fuel pre-igniting in the cylinder, which can cause damage in high-compression engines. Lower octane fuels are more susceptible to this pre-ignition. In the U.S., fuel grades are typically categorized as regular (87 octane), mid-grade (89 octane), and premium (91+ octane). However, these labels can vary regionally. The octane rating you see at the pump is calculated using the (R+M)/2 method, which is an average of the Research Octane Number (RON) and the Motor Octane Number (MON).
Costco’s Fuel Lineup Basics
Costco offers three types of fuel at their over 600 U.S. stations: regular, plus (mid-grade), and supreme (premium), all under the Kirkland Signature brand. To access these, you need a Costco membership, which comes with an annual fee of $60. This membership also comes with certain gas purchasing limits. Before you head to a Costco gas station, it’s important to know a few things. For instance, station hours are typically from 6 a.m. to 10 p.m., and there can be long wait times during peak hours.
Decoding Costco Premium Octane
There’s been some debate about the octane rating of Costco’s supreme gas. While it’s generally accepted that it’s rated at 91 AKI in most states, there’s some debate about whether it reaches 93 in certain areas like California due to TOP TIER standards. The octane rating can also vary based on location, with higher ratings in high-altitude regions or states with stricter emissions rules. To clear up any confusion, it’s best to check the pump labels and supplier information, as Costco sources its fuel from major refiners.
Quality Standards for Costco Gas
Costco adheres to TOP TIER detergent additives in its fuel, which exceed the EPA’s minimum requirements for engine cleanliness. Independent lab tests have shown that Costco’s fuel performs equivalently to competitors like Shell or Exxon. In terms of practical quality checks, there have been no reported widespread issues with contamination or ethanol content in Costco’s fuel.
Cost Benefits of Costco Fuel
One of the major draws of Costco’s fuel is the cost savings. On average, you can save 20-30 cents per gallon on premium gas compared to nearby stations. This can add up to significant savings, especially for drivers with high-octane needs. For instance, one driver joined Costco specifically to fuel his Ferrari with Costco’s cheap premium gas. If you have a large tank, you can maximize your membership value by filling up at Costco, but be sure to avoid any surcharges for non-members.
Does Octane Level Affect Your Drive?
The octane level of your fuel can indeed affect your drive, but the extent of this impact depends on your vehicle. For example, turbocharged engines require premium fuel to prevent damage, while standard cars can run fine on regular 87 octane fuel. Your vehicle’s manual will typically provide recommendations for the minimum octane level. In terms of fuel economy and emissions, general studies have shown minimal differences for most drivers if their vehicle’s octane needs are below 91 AKI.
Practical Tips for Costco Gas Users
Before you select Costco’s supreme gas, check your owner’s manual for the required octane level to avoid unnecessary costs. There are also apps available that can help you locate Costco gas stations and compare real-time prices, all while integrating with membership perks like cash back. Keep an eye out for promotions or loyalty programs that can further enhance your savings. And remember, as of 2024, there have been no major changes to Costco’s fuel availability.