ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has increased the online retail price of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart package. This bundle includes two 5-quart bottles and covers multiple common viscosity grades. Additionally, Costco has introduced a purchase restriction on this item, allowing members to buy no more than two units in a single transaction within a seven-day span. The restriction is visible on select Kirkland Signature motor oil listings on the company’s website.
This new pricing represents a significant jump from levels seen roughly a year ago, when the same quantity sold for about $30. Currently, several Kirkland full synthetic options—such as 5W-30, 5W-20, and 0W-20—are priced at $57.99 online. It’s worth noting that in-store prices may differ from online rates and can vary depending on location. Each package contains 10 quarts, making this change particularly notable for consumers purchasing oil for routine vehicle maintenance.
The purchase restrictions extend beyond Kirkland motor oil to include several Mobil 1 products also sold through Costco. As an ExxonMobil brand, Mobil 1 is among the most recognizable synthetic motor oil labels in the United States. Now, select six-packs of one-quart bottles are limited to five units per membership. The affected listings include both standard and high-mileage formulations across various viscosity grades, thus encompassing more than just Costco’s private-label oil and covering a major national lubricant brand.
Purchase limits extend beyond Kirkland motor oil
The production of synthetic motor oil relies heavily on refined base oils and additives that meet current engine protection standards. Group III base oils are a critical component of many synthetic lubricants. The United States depends on foreign suppliers for a large portion of these materials, with producers in the Persian Gulf providing a substantial 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 throughout the lubricant industry.
Meanwhile, crude oil prices stayed above $100 per barrel in mid-September. On September 16, Brent crude traded near $107.82, and West Texas Intermediate hovered around $104.86. Energy markets continue to react to disturbances impacting major Middle East production and shipping routes. Shipping through the Strait of Hormuz remains well below typical levels, and disruptions at Saudi export infrastructure on the Red Sea have further strained regional petroleum supplies.
Broader supply issues impact the synthetic oil sector
Kirkland products affected by these price and purchase limit changes include various grades used in passenger cars, SUVs, and light trucks. Costco states that these oils deliver wear protection and help prevent thermal breakdown. Many formulations meet API SP and ILSAC GF-6A standards, which address engine cleanliness, fuel economy, and wear protection. Mobil 1 options available at Costco also include several standard, fuel-efficient, and high-mileage variants.
Costco has not issued a detailed public explanation for the increased price of Kirkland motor oil or the new purchase restrictions. Its online listings currently display both the $57.99 price and the two-unit purchase limit for specific products. Meanwhile, separate Mobil 1 product pages still show a five-unit limit per membership for numerous formulations. These changes come amid rising crude oil prices and tightening lubricant supplies, with Costco’s limits providing members with clear guidance on current availability and purchase policies.