ISSAQUAH, WASHINGTON / RankWire.AI / – Costco has increased the online cost of its Kirkland Signature full synthetic motor oil to $57.99 for a 10-quart pack, which includes two 5-quart bottles covering multiple common viscosity grades. In addition, the retailer has introduced a purchase restriction, allowing members to buy no more than two units in a single transaction within a seven-day window. This limit is visible on certain Kirkland Signature motor oil listings on the company’s website.
This new price represents a substantial jump from approximately $30 for the same volume recorded about a year earlier. Currently, Costco lists several formulations of Kirkland full synthetic oil at $57.99 online, including 5W-30, 5W-20, and 0W-20. It should be noted that warehouse pricing may differ from online rates and vary based on location. Each package provides 10 quarts, making this price increase particularly significant for consumers who regularly purchase oil for vehicle maintenance.
The purchase restrictions extend beyond Kirkland motor oils to include several Mobil 1 products also sold through Costco. Mobil 1, a brand of ExxonMobil, is among the most recognized names in synthetic motor oils in the United States. Selected six-packs of one-quart bottles now carry a limit of five units per member. These listings feature both standard and high-mileage formulas across various viscosity grades, indicating that the restrictions are not limited to Costco’s private-label oils but also affect a major national lubricant brand.
Limits on purchases extend beyond Kirkland oils
Manufacturing synthetic motor oils relies heavily on refined base oils and additives that conform to current engine protection standards. Group III base oils are crucial components in many synthetic formulations. The United States depends on international suppliers for a significant proportion of these materials, with producers in the Persian Gulf region supplying a large share of global Group III output. Recent disruptions in Middle East energy markets have led to tighter supplies of various petroleum products and refining components used across the lubricant industry.
Meanwhile, crude oil prices have remained above $100 per barrel as of mid-September, with Brent crude trading close to $107.82 on September 16 and West Texas Intermediate near $104.86. Energy markets continue to reflect the impact of disruptions affecting significant Middle East production and shipping routes, including traffic through the Strait of Hormuz, which remains well below typical levels. Additionally, export infrastructure in Saudi Arabia along the Red Sea has experienced interruptions, further straining regional petroleum supply chains.
Broader supply challenges impact the synthetic oil market
Costco’s affected Kirkland oils include grades suitable for many passenger cars, SUVs, and light trucks, with the company stating these oils offer wear protection and help prevent thermal breakdown. Several formulations meet API SP and ILSAC GF-6A performance standards, which ensure engine cleanliness, fuel efficiency, and resistance to certain types of wear. The Mobil 1 offerings available at Costco also include various standard, fuel-economy, and high-mileage options, with the same purchase limits in place.
The company has not issued a detailed explanation for the price hike of Kirkland motor oil or the new purchase restrictions. Its online listings currently display both the $57.99 price tag and the two-unit purchase limit for certain products. Meanwhile, separate Mobil 1 pages continue to show a five-unit limit per membership on several formulations. These changes come during a period marked by elevated crude oil prices and constrained lubricant supply, with Costco’s posted limits providing members with clear guidance on current stock availability and purchasing policies.