ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has raised 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 and is available in multiple viscosity grades popular among consumers. Additionally, the retailer has introduced a purchase restriction on select Kirkland motor oil products, allowing members to buy no more than two units per transaction within any seven-day window.
This new $57.99 price is nearly twice the approximately $30 that was reported for the same quantity last year. Costco currently offers 5W-30, 5W-20, and 0W-20 full synthetic oils under the Kirkland brand at that online price. The company notes that prices can vary between individual warehouses and those listed online. Since each case holds 10 quarts, this increase is particularly relevant to consumers performing routine oil changes themselves.
The purchase limits extend beyond Costco’s private-label offerings. Some Mobil 1 full synthetic motor oils now also carry a cap of five units per membership. Mobil 1, a brand owned by ExxonMobil, comes in several formulations, including standard and high-mileage types. The restrictions include six-packs of one-quart bottles across various viscosity grades, broadening the scope of the limits to another major synthetic oil line.
Costco’s restrictions affect key synthetic oil products
Synthetic motor oils rely on highly refined base oils mixed with additives that safeguard engines under tough conditions. Group III base oils are essential in many synthetic lubricants sold in the United States. U.S. consumers depend heavily on imported supplies, including those produced in the Persian Gulf. Disruptions in Middle Eastern energy markets have recently limited availability for certain petroleum products and lubricant components.
Crude oil prices also remained elevated above $100 a barrel in mid-September. On September 16, Brent crude traded close to $107.82, with West Texas Intermediate near $104.86. Ongoing energy market disruptions, including impacts on production, exports, and key shipping lanes in the Middle East, continue to influence prices. Shipping through the Strait of Hormuz remains below normal levels, while issues have also affected Saudi Arabia’s Red Sea energy infrastructure.
Rising oil costs align with tighter lubricant supply restrictions
The impacted Kirkland products are designed for a range of passenger cars, SUVs, and light trucks. Costco states that its synthetic oils help prevent engine wear and thermal breakdown. Certain formulations meet API SP and ILSAC GF-6A standards, which are aimed at modern gasoline engines. The American Petroleum Institute manages API motor oil standards, while ILSAC specifications focus on fuel efficiency, engine cleanliness, and wear protection.
Costco has not provided an extensive public explanation for the increased Kirkland motor oil prices or the new purchase restrictions. Its online listings now show the $57.99 price tag and a limit of two units per week on selected items. Meanwhile, Mobil 1 products continue to list a five-unit purchase limit across multiple formulations. These changes reflect the broader context of rising crude oil prices and limited lubricant supplies in the market.