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 contains two 5-quart bottles across various common viscosity grades. The retailer has also introduced 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 price of $57.99 represents nearly double the approximately $30 cost reported for the same quantity last year. Costco now lists Kirkland 5W-30, 5W-20, and 0W-20 full synthetic oils at this increased online rate. Actual prices at physical warehouse locations may differ from those listed online. This price adjustment primarily impacts customers purchasing larger quantities for regular vehicle maintenance, as each Kirkland package provides 10 quarts of synthetic motor oil.
Additionally, Costco has set purchase limits on selected Mobil 1 synthetic motor oils. Mobil 1, a brand owned by ExxonMobil, appears in several Costco listings with a cap of five units per membership. These restricted products include six-packs of one-quart bottles across multiple viscosity grades. Some listings feature standard formulations, while others include high-mileage variants. Consequently, these restrictions apply not only to Costco’s private-label Kirkland motor oils but also to certain Mobil 1 products from a major national lubricant manufacturer.
Restrictions Extend Beyond Kirkland Brand Oils
Synthetic motor oils depend on refined base oils and additive packages designed to safeguard engines under high temperatures and heavy use. Many synthetic lubricants sold in the United States incorporate Group III base oils, which are produced using different refining processes. A significant portion of these supplies is imported from overseas, including facilities in the Persian Gulf. Recent disruptions within Middle East energy markets have reduced the availability of some petroleum-based products and created supply chain constraints for lubricants.
Crude oil prices remained above $100 a barrel in mid-September, with Brent crude trading near $107.82 on September 16. West Texas Intermediate crude oil hovered around $104.86. Ongoing disruptions in Middle East energy production, export routes, and shipping, particularly through the Strait of Hormuz, continue to impact the supply chain. Saudi Arabia’s Red Sea energy infrastructure also faced interruptions, putting additional pressure on petroleum markets and the broader network of refined products and lubricants.
Rising Crude Prices Contribute to Tighter Lubricant Supplies
The Kirkland synthetic oils in question are used in numerous passenger cars, SUVs, and light trucks. Costco claims its full synthetic products help prevent engine wear and thermal degradation. Several formulations meet API SP and ILSAC GF-6A standards, which are designed for modern gasoline engines. Managed by the American Petroleum Institute, these standards address engine performance, fuel economy, cleanliness, and wear protection, all of which are featured on various Kirkland synthetic oil listings.
Costco has not provided an explicit public explanation for the recent increase in Kirkland motor oil prices or the new purchase restrictions. Its website currently displays the $57.99 price tag and a limit of two units per week on certain Kirkland products. Meanwhile, listings for Mobil 1 continue to show a five-unit limit per membership for several formulations. These changes come amidst elevated crude oil prices and reduced lubricant availability, with the posted purchase limits now defining how much members can acquire via the affected online listings.