ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has elevated the online cost of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart set. The package contains two 5-quart bottles and spans several popular viscosity grades. Additionally, Costco has imposed purchase limits on this product, allowing members to buy no more than two units per transaction within a seven-day window. These restrictions are visible on select Kirkland Signature motor oil listings on the retailer’s website.
This new pricing represents a significant rise from figures recorded about a year ago, when the same quantity was sold for approximately $30. Currently, Costco lists multiple formulations of Kirkland full synthetic oil online at $57.99, including 5W-30, 5W-20, and 0W-20. It is important to note that warehouse pricing can differ from online prices and may vary based on location. Each package provides 10 quarts, making this price increase notable for customers who routinely purchase oil for vehicle maintenance.
In addition to Kirkland products, purchase restrictions now also apply to several Mobil 1 items sold via Costco. Mobil 1, a brand owned by ExxonMobil, is among the most recognized synthetic motor oil labels in the United States. Selected six-packs of one-quart bottles are now limited to five units per membership. These affected listings include both standard and high-mileage formulations across various viscosity grades. Therefore, the restrictions extend beyond Costco’s private-label oils to include a major national brand.
Restrictions Extend Beyond Kirkland Motor Oil
The production of synthetic motor oils relies on refined base oils and additives that meet modern engine protection standards. Group III base oils constitute a key component of many synthetic lubricants. The United States depends on foreign suppliers for a significant portion of these materials, with producers in the Persian Gulf contributing a large share of global Group III output. Recent disruptions in Middle East energy markets have led to tighter supplies of various petroleum products and refining inputs used in lubricant manufacturing.
Crude oil prices stayed above $100 a barrel in mid-September, with Brent crude trading near $107.82 on September 16 and West Texas Intermediate around $104.86. The energy markets continued to reflect disturbances impacting key Middle East production and shipping routes. Shipping traffic through the Strait of Hormuz remained significantly below normal, and Saudi export infrastructure on the Red Sea faced interruptions, further straining regional petroleum supply chains.
Broader Supply Challenges for Synthetic Oils
Costco’s affected Kirkland oils include grades used widely in passenger cars, sport utility vehicles, and light trucks. The retailer states these oils provide protection against wear and help regulate thermal breakdown. Several formulations comply with API SP and ILSAC GF-6A performance standards, which address engine cleanliness, fuel economy, and wear protection. The Mobil 1 offerings at Costco also include several standard, fuel-economy, and high-mileage options.
A detailed explanation from Costco regarding the increase in Kirkland motor oil prices or the new purchase restrictions has not been provided. Presently, its online listings display both the $57.99 price and the two-unit purchase limit for selected products. Meanwhile, separate Mobil 1 pages show a five-unit limit per membership on various formulations. These changes come amidst elevated crude oil prices and constrained lubricant supplies, with Costco’s posted limits offering members clear guidance on current purchasing rules and product availability.