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 case. Each package includes two 5-quart bottles and is available in several common viscosity grades. Additionally, the retailer has implemented purchase restrictions on certain Kirkland motor oil products. According to current online listings, members are limited to buying a maximum of two units per transaction within a seven-day period.
The new $57.99 price marks a significant rise from last year’s approximate $30 for the same quantity. Costco offers Kirkland 5W-30, 5W-20, and 0W-20 full synthetic oils at this elevated online cost. Prices may vary at physical warehouse stores compared to those listed online. This change particularly impacts customers who purchase larger quantities for routine vehicle upkeep, given that each Kirkland package provides 10 quarts of synthetic motor oil.
Costco has also placed purchase limits on select Mobil 1 synthetic motor oils. The ExxonMobil brand appears in several Costco listings with a cap of five units per membership. These restrictions apply to six-packs of one-quart bottles across different viscosity grades, including standard formulations and high-mileage variants. Consequently, the limits cover both Costco’s private-label Kirkland oils and certain products from a major national lubricant brand.
Restrictions on motor oil extend beyond Kirkland offerings
Synthetic motor oil production depends on refined base oils and additives engineered to safeguard engines under heat and heavy use. Group III base oils are integral to many synthetic lubricants sold in the United States. American consumers rely heavily on imports from overseas producers, including facilities in the Persian Gulf. Ongoing disruptions in Middle East energy markets have limited the availability of certain petroleum products and constricted parts of the lubricant supply chain.
In mid-September, crude oil prices stayed above $100 per barrel. Brent crude traded around $107.82 on September 16, while West Texas Intermediate hovered near $104.86. Continued supply disruptions in the Middle East impacted production, exports, and shipping routes. Shipping through the Strait of Hormuz remained below normal levels, and Saudi Arabia’s Red Sea energy infrastructure also faced interruptions, increasing pressure on petroleum markets and the broader supply chain for refined products and lubricants.
Rising crude oil costs lead to tighter lubricant supplies
Costco’s Kirkland synthetic oils serve a broad range of passenger vehicles, SUVs, and light trucks. The company emphasizes that its full synthetic oils help prevent engine wear and thermal stress. Many formulations meet API SP and ILSAC GF-6A standards, which are set for modern gasoline engines. The API standards are managed by the American Petroleum Institute, and ILSAC specifications include considerations like fuel economy, engine cleanliness, and wear protection. These certifications are indicated on several Kirkland synthetic oil listings.
Costco has yet to publicly explain the reasons behind the price hike for Kirkland motor oils or the new purchase restrictions. Its website currently displays the $57.99 price along with a two-unit limit per week on selected products. Meanwhile, separate listings for Mobil 1 continue to specify a five-unit purchase limit per membership for various formulations. The policy adjustments coincide with higher crude oil prices and tighter lubricant supplies, with online restrictions now defining the quantities members can purchase for affected products.