ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has raised the online retail price of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart case, which includes two 5-quart bottles across several common viscosity grades. Alongside this price adjustment, the retailer has introduced a purchase cap on selected Kirkland motor oil items, restricting members to a maximum of two units per transaction within a seven-day window, according to current online listings from Costco.
The newly listed $57.99 cost is nearly double the approximate $30 price observed for the same quantity last year. The elevated online price applies to Kirkland 5W-30, 5W-20, and 0W-20 full synthetic oils. It should be noted that prices at physical warehouse locations might differ from those displayed online. This change impacts customers who buy larger quantities for regular vehicle upkeep, since each Kirkland package contains 10 quarts of synthetic motor oil.
In addition to the Kirkland brand, Costco has imposed purchase restrictions on certain Mobil 1 synthetic motor oils. As a product of ExxonMobil, Mobil 1 appears in multiple Costco listings with a limit of five units per membership. These restrictions cover six-packs of one-quart bottles in various viscosity grades, including both standard formulations and high-mileage variants. Consequently, the purchase limits affect not only Costco’s private-label Kirkland oils but also selected Mobil 1 products from a major national lubricant supplier.
Limits on motor oil extend beyond Kirkland products
Synthetic motor oil manufacturing depends on refined base oils and additives crafted to safeguard engines under high temperatures and heavy usage. Group III base oils are a key element in numerous synthetic lubricants sold in the United States. A significant portion of these supplies is imported by American buyers from overseas producers, including facilities located in the Persian Gulf. Recently, disruptions in Middle Eastern energy markets have led to reduced availability of certain petroleum products and tightened supply chains for lubricants.
Crude oil prices remained above $100 per barrel in mid-September, with Brent crude trading near $107.82 on September 16 and West Texas Intermediate close to $104.86. Ongoing disruptions in the Middle East have continued to influence oil production, exports, and shipping routes, with traffic through the Strait of Hormuz staying below typical levels. Additionally, interruptions to Saudi Arabia’s Red Sea energy infrastructure have further intensified pressure on petroleum markets and the broader network supplying refined products and lubricants.
Rising crude oil prices intensify lubricant supply constraints
The affected Kirkland synthetic oils are used in many passenger vehicles, SUVs, and light trucks, with Costco asserting that its full synthetic offerings help shield engines from wear and thermal degradation. Certain products meet API SP and ILSAC GF-6A standards, which are intended for modern gasoline engines. The API standards are managed by the American Petroleum Institute, while ILSAC specifications cover aspects such as fuel economy, engine cleanliness, and wear protection, all of which are listed on several Kirkland synthetic oil products.
Costco has not provided a detailed public explanation for the recent increase in Kirkland motor oil prices or the new purchase limits. The current online listings display the $57.99 price tag along with a restriction of two units per seven days on selected products. Meanwhile, Mobil 1 offerings continue to show a five-unit limit per membership across various formulations. These adjustments coincide with elevated crude oil prices and tighter lubricant supply chains, while the current limits outline the maximum quantity members can purchase through affected online listings.