ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has increased the online price of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart package, which includes two 5-quart bottles and spans several common viscosity grades. The retailer also implemented a purchase restriction, allowing members to buy no more than two units per transaction within a seven-day window. This limitation appears on select Kirkland Signature motor oil listings on the company’s website.
This new pricing represents a significant jump from levels recorded approximately a year ago, when the same quantity was priced around $30. Currently, Costco lists multiple Kirkland full synthetic formulations online at $57.99, such as 5W-30, 5W-20, and 0W-20. It’s important to note that warehouse prices might differ from online prices and vary by location. Each package provides 10 quarts, making this price increase especially relevant for customers who regularly purchase oil for vehicle maintenance.
Restrictions on purchase quantities also extend to several Mobil 1 products available through Costco. As an ExxonMobil brand, Mobil 1 is among the most recognizable synthetic motor oil brands in the US. Selected six-packs of one-quart bottles are now limited to five units per membership, including various formulations such as standard and high-mileage options across multiple viscosity grades. These limits cover more than just Costco’s private-label oil, encompassing a major national lubricant brand as well.
Limits Extend Beyond Kirkland Oil
The production of synthetic motor oil relies heavily on refined base oils and additives that satisfy modern engine protection standards. Group III base oils, a key component of many synthetic formulations, are predominantly supplied from overseas. The United States depends significantly on suppliers from abroad for these materials, with the Persian Gulf supplying a large portion of the global Group III output. Recent disruptions in Middle East energy markets have restricted supplies of various petroleum products and refining inputs used throughout the lubricant industry.
Meanwhile, crude oil prices stayed above $100 a barrel in mid-September, with Brent crude near $107.82 on September 16 and West Texas Intermediate around $104.86. Energy markets continue to reflect ongoing disruptions affecting major Middle East production and shipping routes, with traffic through the Strait of Hormuz remaining well below normal levels. Additionally, interruptions at Saudi export infrastructure on the Red Sea have contributed to the pressure on regional petroleum supplies.
Broader Supply Constraints Hit Synthetic Oil
Kirkland products affected by Costco include grades used in passenger cars, SUVs, and light trucks. The company states that these oils offer protection against wear and help manage thermal breakdown. Several formulations meet API SP and ILSAC GF-6A performance standards, which encompass engine cleanliness, fuel efficiency, and protection from certain types of wear. The Mobil 1 listings at Costco also feature various standard, high-mileage, and fuel-economy options.
Costco has not issued a detailed public explanation for the increased prices of Kirkland motor oil or the new purchase limits. Its online listings currently display both the $57.99 price and the two-unit purchase restriction for select products. Meanwhile, separate Mobil 1 pages continue to show a five-unit membership limit on several formulations. These changes come amid elevated crude oil prices and a tighter lubricant supply, with Costco’s posting of limits helping members understand the current availability and purchasing policies clearly.