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 set, which includes two 5-quart bottles covering various common viscosity grades. Additionally, the retailer has imposed a purchase cap, allowing members to buy no more than two units per transaction within a seven-day span. This restriction is visible on select Kirkland Signature motor oil listings on the company’s website.
This new price represents a significant jump from levels seen roughly a year ago, when the same quantity was priced around $30. Currently, Costco offers several Kirkland full synthetic formulations at $57.99 online, including 5W-30, 5W-20, and 0W-20, though in-store prices may vary by location. Each package contains 10 quarts, making the price hike particularly notable for consumers purchasing oil for routine vehicle maintenance.
The purchase limits also extend to certain Mobil 1 products available through Costco. As an ExxonMobil brand, Mobil 1 is among the most recognizable synthetic motor oil brands in the US. Now, six-packs of one-quart bottles are limited to five units per membership. The affected listings include both standard and high-mileage formulations across multiple viscosity grades, indicating that restrictions go beyond Costco’s private-label oils and encompass a major national lubricant brand.
Restrictions Extend to Other Major Synthetic Oil Brands
The production of synthetic motor oils relies on refined base oils and additives that meet modern engine standards. Group III base oils, crucial for many synthetic lubricants, depend heavily on imported supplies. The United States sources a large share of these materials from overseas, particularly from producers in the Persian Gulf. Recent disruptions in Middle East energy markets have tightened supplies of petroleum products and refining inputs used in the lubricant industry.
Crude oil prices also remained above $100 a 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, affecting key production and shipping routes such as the Strait of Hormuz and Red Sea infrastructure, continue to impact energy markets and supply chains.
Wider Market Strains Affect Synthetic Oil Availability
Costco’s affected Kirkland oils include grades suitable for many passenger cars, SUVs, and light trucks, offering protection from wear and thermal breakdown. Several formulations comply with API SP and ILSAC GF-6A performance standards, emphasizing engine cleanliness, fuel efficiency, and wear protection. Mobil 1 products available at Costco also include various standard, high-mileage, and fuel-economy options.
The company has not provided an official explanation for the increased Kirkland motor oil prices or the new purchase limits. The online listings currently display both the $57.99 price and the two-unit purchase restriction for select items. Meanwhile, separate Mobil 1 product pages continue to show five-unit limits per membership on multiple formulations. These changes occur amid rising crude prices and tighter lubricant supplies, with Costco’s posted limits offering members clarity on current availability and purchasing policies.