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 case, which contains two 5-quart bottles in various common viscosity grades. Additionally, the retailer has set a purchase cap on specific Kirkland motor oil items, allowing members to buy no more than two units per transaction within a seven-day window, according to current online listings on Costco’s website.
The new price of $57.99 nearly doubles the approximately $30 cost reported for the same quantity last year. Costco lists Kirkland 5W-30, 5W-20, and 0W-20 full synthetic oils at this increased online rate. Prices at warehouse locations may vary from those displayed online. This change impacts customers purchasing larger quantities for regular vehicle upkeep, as each Kirkland package contains 10 quarts of synthetic motor oil.
Restrictions have also been placed on selected Mobil 1 synthetic motor oil products by Costco. Mobil 1, an ExxonMobil brand, appears in multiple listings with a limit of five units per membership. The products affected include six-packs of one-quart bottles across several viscosity grades. Some listings feature standard formulations, while others include high-mileage options. The restrictions therefore extend to both Costco’s private-label Kirkland oil and certain products from a well-known national lubricant brand.
Limits on motor oil extend beyond Kirkland offerings
Synthetic motor oil production depends on refined base oils and additives engineered to safeguard engines under high heat and heavy load conditions. Group III base oils are a significant component in many synthetic lubricants sold in the United States. A substantial portion of these supplies are imported by American buyers from overseas producers, including facilities in the Persian Gulf. Recent disruptions in Middle East energy markets have decreased the availability of some petroleum products and tightened parts of the lubricant supply chain.
In mid-September, crude oil prices remained above $100 per barrel. Brent crude traded near $107.82 on September 16, while West Texas Intermediate was around $104.86. Ongoing supply disruptions in the Middle East continued to influence production, exports, and shipping routes, with traffic through the Strait of Hormuz remaining below normal. Saudi Arabia’s Red Sea energy infrastructure also experienced interruptions, adding strain to petroleum markets and the broader network responsible for supplying refined products and lubricants.
Rising crude oil prices coincide with tighter lubricant availability
Many passenger cars, SUVs, and light trucks rely on the affected Kirkland motor oils. Costco states that its full synthetic oils are designed to protect engines from wear and thermal breakdown. Certain products meet API SP and ILSAC GF-6A performance standards suitable for modern gasoline engines. The API sets motor oil standards, while ILSAC specifications address aspects such as fuel economy, engine cleanliness, and wear protection. These standards are listed on several Kirkland synthetic oil product pages.
Costco has not provided an elaborate public explanation for the increase in Kirkland motor oil prices or the new purchase restrictions. Its website presently displays the $57.99 price point along with a two-unit seven-day limit on selected Kirkland products. Meanwhile, individual Mobil 1 listings continue to show a five-unit limit per membership for various formulations. These changes occur during a period of elevated crude oil prices and tighter lubricant supplies, with Costco’s posted limits now determining members’ online purchase quantities for affected products.