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 package. This package includes two 5-quart bottles and is available in several typical viscosity grades. The retailer now enforces a limit of one transaction per member and a maximum of two units within a seven-day period. These restrictions are explicitly displayed on the product pages for selected Kirkland Signature synthetic motor oils.
The new $57.99 price marks a substantial jump from approximately $30 for the same quantity reported last year. Currently, Costco lists its 5W-30, 5W-20, and 0W-20 full synthetic two-packs at this price online. The retailer highlights that warehouse prices can differ depending on location. Each pack provides 10 quarts of motor oil, making this price increase particularly notable for members who do their own vehicle maintenance.
Additionally, Costco has imposed purchase limits on various Mobil 1 full synthetic motor oil products. Listed now are a restriction of five units per membership on select six-packs containing one-quart bottles. These products include several viscosity options and high-mileage formulations. The restrictions extend beyond Costco’s Kirkland Signature line and include another widely purchased synthetic motor oil brand available through the warehouse retailer.
Purchase restrictions apply to multiple synthetic motor oil options
Synthetic motor oils are formulated from highly refined base oils combined with additives that protect engines, control deposits, reduce wear, and withstand thermal stress. Group III base oils are a critical component in the supply chain for many synthetic lubricants. The United States imports a significant portion of these materials from producers in the Persian Gulf region. Recent disruptions impacting energy production and shipping in the Middle East have caused tighter supplies of some petroleum products and refining inputs.
Crude oil prices also remain elevated as of mid-September. On September 16, Brent crude traded near $107.82 per barrel, while West Texas Intermediate hovered around $104.86. Both benchmarks stayed above $100 after weeks of disruptions affecting key energy routes in the Middle East. Shipping through the Strait of Hormuz has dropped sharply from normal levels, with interruptions impacting Saudi Arabia’s Red Sea export infrastructure and other regional energy facilities.
Rising crude oil prices influence petroleum markets broadly
The Kirkland Signature products subject to purchase limits include popular grades used across a wide spectrum of passenger vehicles. Costco states its synthetic motor oils offer wear protection and help mitigate thermal breakdown. Several formulations of Kirkland oils also meet API SP and ILSAC GF-6A performance standards. The Mobil 1 products available at Costco include standard, fuel-economy, and high-mileage options, with purchase restrictions clearly shown on multiple product pages.
No detailed public explanation has been provided by Costco regarding the recent price hikes and imposed purchase caps on motor oils. However, its online listings now distinctly display both the $57.99 Kirkland price and the two-unit limit per week. Meanwhile, Mobil 1 listings continue to show a five-unit limit per membership. These developments come amid rising petroleum prices and limited lubricant availability, situating Costco’s pricing and purchase restrictions within a broader context of tight energy markets.