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 set. The package includes two 5-quart bottles and spans multiple common viscosity grades. The retailer also introduced a purchase limit on this product, allowing members to buy no more than two units in a single transaction within a seven-day span. This restriction can be seen on certain Kirkland Signature motor oil listings on Costco’s website.
This new pricing represents a significant jump from levels observed roughly a year earlier, when the same quantity was available for about $30. Currently, Costco lists various formulations of Kirkland full synthetic oils online at $57.99, including 5W-30, 5W-20, and 0W-20. It’s worth noting that store prices may differ from those online and could vary depending on location. Each package contains 10 quarts, making this price increase especially notable for customers who regularly purchase oil for vehicle maintenance.
The purchase limits extend beyond Kirkland products, applying also to several Mobil 1 oils sold through Costco. Mobil 1, a brand owned by ExxonMobil, is among the most recognized synthetic motor oil labels in the United States. Selected six-packs of one-quart bottles are now limited to five units per membership. These restrictions include both standard and high-mileage formulations across multiple viscosity grades, thereby affecting a major national lubricant brand in addition to Costco’s private-label oils.
Restrictions Extend to Other Synthetic Motor Oils as Well
Producing synthetic motor oils involves refined base oils and additives that meet current engine protection standards. Group III base oils are integral to many synthetic formulations. The United States depends on international suppliers for a large portion of these materials, with the Persian Gulf region supplying a significant share of global Group III output. Recent disruptions in Middle East energy markets have constrained supplies of various petroleum products and refining inputs used across the lubricant industry.
In mid-September, crude oil prices stayed above $100 per barrel. Brent crude was near $107.82 on September 16, while West Texas Intermediate hovered around $104.86. Market conditions remain affected by ongoing disruptions in major Middle East production and shipping routes. Traffic through the Strait of Hormuz stayed well below typical levels, and Saudi Red Sea export infrastructure faced interruptions, adding further pressure to regional petroleum supply chains.
The Broader Synthetic Oil Market Faces Increased Supply Pressures
The Kirkland oils affected by Costco include grades suitable for many passenger vehicles, SUVs, and light trucks. The retailer states these oils offer protection against engine wear and assist in managing thermal breakdown. Some formulations meet API SP and ILSAC GF-6A standards, which encompass engine cleanliness, fuel efficiency, and wear protection. The Mobil 1 products available at Costco also include several standard, fuel-economy, and high-mileage options.
Costco has not provided an explicit public explanation for the increased prices of Kirkland motor oils or the introduction of purchase restrictions. Currently, online listings show both the $57.99 price and the two-unit purchase limit for selected items. Meanwhile, separate Mobil 1 listings continue to specify a five-unit limit per membership across various formulations. These changes come amid elevated crude oil prices and tightening lubricant supplies, with Costco’s posted limits helping members understand current availability and purchasing policies.